Compare Claude Opus 4.8 and Claude Sonnet 4.6: Frontier Rigor vs Coding Efficiency
Claude Opus 4.8 vs Claude Sonnet 4.6: which should I use?
Claude Sonnet 4.6 provides balanced coding and agent performance ($3.00/$15.00 per million tokens, 200K context), while Claude Opus 4.8 delivers deep analytical reasoning and 500K context ($5.00/$25.00 per million tokens). Verified 2026-09-07.
Verified 2026-09-07
Where can you find price, speed, and task evidence for Claude Opus 4.8 and Claude Sonnet 4.6?
Which tasks fit Claude Opus 4.8 and Claude Sonnet 4.6?
Best-fit task signals from the published model strengths; this is not a substitute for a controlled benchmark.
| Fact | Claude Opus 4.8 | Claude Sonnet 4.6 |
|---|---|---|
| Best fit | Complex, multi-step tasks where Fable 5’s premium isn’t justified. | Enterprise workloads that need Opus-adjacent quality at Sonnet pricing. |
| Reasoning mode | Available | Available |
What does a Coding Agent workload cost with Claude Opus 4.8 and Claude Sonnet 4.6?
Modeled for Coding Agent: 20,000 input + 2,000 output tokens per task, 1 turn. This is a workload model, not a provider quote.
| Fact | Claude Opus 4.8 | Claude Sonnet 4.6 |
|---|---|---|
| Coding Agent / task | $0.15 (modeled) | $0.09 (modeled) (winner) |
| Input / output rate | $5.00 / $25.00 per M | $3.00 / $15.00 per M |
How fast are Claude Opus 4.8 and Claude Sonnet 4.6?
Only non-estimated benchmark results are shown as measured.
| Fact | Claude Opus 4.8 | Claude Sonnet 4.6 |
|---|---|---|
| Measured throughput | 58 tokens/s | 76 tokens/s (winner) |
| Time to first token | 470 ms | 360 ms |
How compatible are Claude Opus 4.8 and Claude Sonnet 4.6 with APIs?
Provider-level wire-format and SDK facts; model-specific parameter differences may still apply.
| Fact | Claude Opus 4.8 | Claude Sonnet 4.6 |
|---|---|---|
| OpenAI SDK | Not drop-in | Not drop-in |
| Request shape | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. |
| Streaming | SSE (Anthropic content-block events) | SSE (Anthropic content-block events) |
What are the privacy and retention policies for Claude Opus 4.8 and Claude Sonnet 4.6?
Provider policy and residency facts from the verified provider registry. A missing retention policy is not treated as a guarantee.
| Fact | Claude Opus 4.8 | Claude Sonnet 4.6 |
|---|---|---|
| Provider says API data trains models | No | No |
| Published retention period | Unavailable | Unavailable |
| Data residency | Unavailable | Unavailable |
How much effort does it take to migrate between Claude Opus 4.8 and Claude Sonnet 4.6?
Direction is from each displayed model to the other. Effort is derived from provider compatibility and published parameter maps.
| Fact | Claude Opus 4.8 | Claude Sonnet 4.6 |
|---|---|---|
| Move Claude Opus 4.8 → Claude Sonnet 4.6 | drop-in; 0 breaking parameter differences | Target: Claude Sonnet 4.6 |
| Move Claude Sonnet 4.6 → Claude Opus 4.8 | Source: Claude Sonnet 4.6 | drop-in; 0 breaking parameter differences |
| Why | Same provider; only the model identifier changes. | Same provider; only the model identifier changes. |
Exact-pair cutover and operating-tier guide. Verified 2026-09-02. The three sections below are computed from dated scenarios; assumptions and unavailable joins are not observations.
Exact pair boundary: Anthropic; premium-versus-balanced exact IDs; effort, host, tool policy, and lifecycle must be matched. Requested models are claude-opus-4-8 and claude-sonnet-4-6. Provider, rate, pricing, and task pages remain fact owners.
Opus/Sonnet effort-normalization ledger
Frozen scenario board. Formula / deterministic rule: comparable = exact host/surface/ID + provider control/value + tool policy + reasoning accounting + prompt hash; mismatch => exclude Boundary: Only Opus 4.8 versus Sonnet 4.6 effort comparability is owned; no broad Claude tier or task ranking is emitted.
| Frozen scenario | Pair, host, surface, and evidence fields | Result | State |
|---|---|---|---|
| default | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; effort=default; host=direct; provider control/value=required; reasoning tokens=required; prompt/config hash=effort-001; tool policy=none; evidence=2026-09-02 | Unavailable — default semantics and token accounting are not joined | NOT COMPARABLE — default unknown |
| low | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; effort=low; host=direct; control/value=low; prompt/config hash=effort-002; reasoning usage=required; result hash=missing; evidence=2026-09-02 | Unavailable — matched low-effort result is absent | UNAVAILABLE — low evidence |
| medium | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; effort=medium; host=direct; control/value=medium; prompt/config hash=effort-003; tools=paired; judge/denominator=required; evidence=2026-09-02 | Unavailable — paired medium acceptance is not joined | UNAVAILABLE — medium evidence |
| high | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; effort=high; host=direct; control/value=high; prompt/config hash=effort-004; reasoning tokens=required; tool policy=paired; evidence=2026-09-02 | Unavailable — high-setting equivalence and raw results are missing | UNAVAILABLE — high evidence |
| maximum | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; effort=maximum; host=direct; control/value=maximum; prompt/config hash=effort-005; output/tool reserve=required; result hash=missing; evidence=2026-09-02 | Treat maximum as a named setting, not a cross-model compute equivalence, until evidence joins. | NOT COMPARABLE — semantics unknown |
| unmatched-tool fixtures | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; effort=high; tool policy=unmatched; prompt/config hash=effort-006; Opus tools=search+write; Sonnet tools=none; side_effect=uncontained; evidence=2026-09-02 | Exclude the fixture because tool access confounds the tier comparison. | NOT COMPARABLE — tool mismatch |
First-party provenance: Anthropic Claude model documentation; verification date 2026-09-02. Missing or conflicting joins fail closed.
Marginal-acceptance value receipt
Frozen scenario board. Formula / deterministic rule: marginal value = avoided failure/review cost − Opus incremental cost; missing matched coverage or rates => Unavailable Boundary: Value is consequence-specific for this exact pair; there is no universal Opus or Sonnet winner.
| Frozen scenario | Pair, host, surface, and evidence fields | Result | State |
|---|---|---|---|
| routine generation | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; cohort=value-001; matched prompt/config/effort hashes=required; accepted result denominator=required; rates=dated; evidence=2026-09-02 | Unavailable — matched acceptance and rate-period joins are missing | UNAVAILABLE — routine value |
| repository repair | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; cohort=value-002; repository/test hashes=paired; tools=paired; rubric=tests+review; accepted results=required; evidence=2026-09-02 | Unavailable — paired patch coverage and incremental cost are absent | UNAVAILABLE — repair value |
| long-document synthesis | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; cohort=value-003; document hash=doc-value-003; context reserve=paired; citation rubric=required; latency=required; evidence=2026-09-02 | Unavailable — paired document acceptance and latency are not observed | UNAVAILABLE — document value |
| strict extraction | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; cohort=value-004; schema hash=paired; validator/denominator=required; output tokens=required; rate owner=dated; evidence=2026-09-02 | Unavailable — schema yield and rates are not joined | UNAVAILABLE — extraction value |
| tool agent | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; cohort=value-005; tool trace hashes=paired; side_effect=contained; acceptance/reviewer=required; attempt cap=2; evidence=2026-09-02 | Unavailable — tool success and escalation cost are unobserved | UNAVAILABLE — agent value |
| high-consequence review | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; cohort=value-006; expert rubric/denominator=required; accepted status=Untested; human review cost=assumption; rate period=dated; evidence=2026-09-02 | Require expert review and keep marginal value Unavailable until matched evidence exists. | BLOCKED — human gate |
First-party provenance: Anthropic API pricing; verification date 2026-09-02. Missing or conflicting joins fail closed.
Sonnet-first/Opus-escalation stop board
Frozen scenario board. Formula / deterministic rule: escalate = observed trigger ∧ attempt cap; promote = acceptance floor + bounded cost/latency + side-effect containment Boundary: This stop board owns exact-pair escalation, not general agent architecture or task selection.
| Frozen scenario | Pair, host, surface, and evidence fields | Result | State |
|---|---|---|---|
| Sonnet-only | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; route=sonnet-only; fixture=stop-001; acceptance floor=declared; trigger=none; attempt cap=1; result/rate hashes=required; evidence=2026-09-02 | Retain Sonnet-only only when the local acceptance floor is observed. Measurement state: labeled assumption only. | ASSUMPTION ONLY — measure floor |
| direct Opus | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; route=opus-direct; fixture=stop-002; consequence=critical; expert rubric=required; effort=matched; rate/latency=dated; evidence=2026-09-02 | Use direct Opus only under a declared consequence rule; expected value remains Unavailable. | CONDITIONAL — consequence rule |
| validator-triggered escalation | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; route=sonnet→opus; fixture=stop-003; schema validator hash=required; trigger rate=assumption; tokens carried forward=declared; attempt cap=2; evidence=2026-09-02 | Expected cost = Sonnet cost + observed trigger rate × Opus cost. Measurement state: labeled assumption only. | ASSUMPTION ONLY — trigger must be measured |
| complexity-triggered escalation | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; route=sonnet→opus; fixture=stop-004; classifier hash=complex-004; trigger evidence=required; cache isolation=required; side_effect=contained; evidence=2026-09-02 | Unavailable — classifier precision and pair acceptance are not observed | UNAVAILABLE — trigger evidence |
| disagreement review | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; route=sonnet+opus→human; fixture=stop-005; disagreement hash=required; reviewer=required; tokens/rates=dated; attempt cap=2; evidence=2026-09-02 | Stop automation and send disagreement to a human; do not select a model from disagreement alone. | BLOCKED — human review |
| repeated failure | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-opus-4-8,claude-sonnet-4-6; effective IDs=claude-opus-4-8,claude-sonnet-4-6; route=sonnet→opus→human; fixture=stop-006; attempt cap=2; failure classes=required; side_effect=settled; rollback/reviewer=required; evidence=2026-09-02 | Stop after the bounded cascade and route to human review. | BLOCKED — terminal human action |
First-party provenance: Anthropic Messages API; verification date 2026-09-02. Missing or conflicting joins fail closed.
Method and limitations: formulas are deterministic; assumptions are labeled; no missing provider, host, account, region, realm, cluster, alias, snapshot, version, artifact, effort, tool, modality, benchmark, workload, rate-period, timestamp, or result is transferred. Run this scenario →
Exact-pair decision guide · verified 2026-09-07
Exact pair boundary: Anthropic; same provider, tier escalation, premier analytical flagship vs capable coding workhorse, and pricing must join. Requested models are claude-opus-4-8 and claude-sonnet-4-6. Provider, rate, pricing, and task pages remain fact owners.
Token pricing and 1.67x enterprise budget impact matrix
Frozen scenario board. Formula / deterministic rule: monthly_spend = calls * ((in_tokens * rate_in + out_tokens * rate_out) / 1M) Boundary: Owns base token tariff comparisons and budget expenditure modeling.
| Frozen scenario | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
| 10K complex code review passes | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=10K complex code review passes; workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 4.6 spend; budget delta; pricing champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 10K complex code review passes is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| 50K multi-file bug triage calls | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=50K multi-file bug triage calls; workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 4.6 spend; budget delta; pricing champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 50K multi-file bug triage calls is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| 100K technical reasoning queries | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=100K technical reasoning queries; workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 4.6 spend; budget delta; pricing champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 100K technical reasoning queries is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| prompt caching active (90% read discount both) | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=prompt caching active (90% read discount both); workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 4.6 spend; budget delta; pricing champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — prompt caching active (90% read discount both) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| batch processing active (50% both) | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=batch processing active (50% both); workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 4.6 spend; budget delta; pricing champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — batch processing active (50% both) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| unresolved pricing currency | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=unresolved pricing currency; workload; prompt tokens; completion tokens; Opus 4.8 spend; Sonnet 4.6 spend; budget delta; pricing champion; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unresolved pricing currency has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: Anthropic API pricing; verification date 2026-09-07. Missing or conflicting joins fail closed.
Context window saturation (500K vs 200K) capability gate
Frozen scenario board. Formula / deterministic rule: eligible = (context <= 200K ? Both : (context <= 500K ? Opus : Excluded)) Boundary: Owns context scaling and capability gating for large repositories.
| Frozen scenario | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
| single module refactor (20K tokens) | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=single module refactor (20K tokens); context size; Opus 4.8 eligible; Sonnet 4.6 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — single module refactor (20K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| medium repository slice (100K tokens) | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=medium repository slice (100K tokens); context size; Opus 4.8 eligible; Sonnet 4.6 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — medium repository slice (100K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| large service codebase (200K boundary) | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=large service codebase (200K boundary); context size; Opus 4.8 eligible; Sonnet 4.6 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — large service codebase (200K boundary) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| monolithic application codebase (400K tokens) | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=monolithic application codebase (400K tokens); context size; Opus 4.8 eligible; Sonnet 4.6 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — monolithic application codebase (400K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| 500K full context saturation test | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=500K full context saturation test; context size; Opus 4.8 eligible; Sonnet 4.6 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 500K full context saturation test is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| unsupported repository archive format | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=unsupported repository archive format; context size; Opus 4.8 eligible; Sonnet 4.6 eligible; Opus cost; Sonnet cost; context gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unsupported repository archive format has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: Anthropic Claude model documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.
Quality floor escalation and defect prevention ROI ledger
Frozen scenario board. Formula / deterministic rule: break_even_accuracy = (opus_cost / sonnet_cost) - 1; defect loss saved justifies Opus spend Boundary: Owns quality break-even analysis and error prevention ROI.
| Frozen scenario | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
| zero defect cost (raw cost comparison) | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=zero defect cost (raw cost comparison); scenario; Sonnet 4.6 spend; Opus 4.8 spend; cost difference; break-even accuracy uplift; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — zero defect cost (raw cost comparison) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| low defect penalty ($15 per bug) | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=low defect penalty ($15 per bug); scenario; Sonnet 4.6 spend; Opus 4.8 spend; cost difference; break-even accuracy uplift; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — low defect penalty ($15 per bug) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| medium defect penalty ($75 per outage) | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=medium defect penalty ($75 per outage); scenario; Sonnet 4.6 spend; Opus 4.8 spend; cost difference; break-even accuracy uplift; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — medium defect penalty ($75 per outage) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| critical security vulnerability ($300 per defect) | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=critical security vulnerability ($300 per defect); scenario; Sonnet 4.6 spend; Opus 4.8 spend; cost difference; break-even accuracy uplift; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — critical security vulnerability ($300 per defect) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| 10% Sonnet retry scenario | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=10% Sonnet retry scenario; scenario; Sonnet 4.6 spend; Opus 4.8 spend; cost difference; break-even accuracy uplift; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 10% Sonnet retry scenario is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| unresolved defect valuation | pair=claude-opus-4-8 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-opus-4-8,claude-sonnet-4-6; scenario=unresolved defect valuation; scenario; Sonnet 4.6 spend; Opus 4.8 spend; cost difference; break-even accuracy uplift; economic verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unresolved defect valuation has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: Anthropic Claude documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.
Method and limitations: formulas are deterministic; observed and assumed inputs are labeled; no missing provider, host, account, region, realm, alias, snapshot, revision, weight, artifact, control, tool, modality, workload, rate-period, timestamp, or result is transferred. Run this scenario →
How do Claude Opus 4.8 and Claude Sonnet 4.6 compare on specs?
| Claude Opus 4.8 | Claude Sonnet 4.6 | |
|---|---|---|
| Price (input) | $5.00/M | $3.00/M ✓ |
| Price (output) | $25.00/M | $15.00/M ✓ |
| Blended price | $10.00/M | $6.00/M ✓ |
| Context window | 500,000 tokens ✓ | 300,000 tokens |
| Max output | 64,000 tokens | 64,000 tokens |
| Modalities | text, vision | text, vision |
| Reasoning mode | Yes | Yes |
| Released | 2026-04 | 2026-03 |
| Speed | 58 t/s | 76 t/s ✓ |
How much do Claude Opus 4.8 and Claude Sonnet 4.6 cost at scale?
| Tokens / month | Claude Opus 4.8 | Claude Sonnet 4.6 | Delta |
|---|---|---|---|
| 1,000,000 | $10.00 | $6.00 | $4.00 (1.7×) |
| 10,000,000 | $100.00 | $60.00 | $40.00 (1.7×) |
| 100,000,000 | $1000.00 | $600.00 | $400.00 (1.7×) |
Choose Claude Opus 4.8 if…
- ✓Elite coding and multi-step reasoning
- ✓Strong instruction following on ambiguous prompts
- ✓Extended-thinking mode
- ✓Complex, multi-step tasks where Fable 5’s premium isn’t justified.
Choose Claude Sonnet 4.6 if…
- ✓Best intelligence-per-dollar in the Claude lineup
- ✓Fast enough for interactive coding agents
- ✓Reliable structured output
- ✓Enterprise workloads that need Opus-adjacent quality at Sonnet pricing.
Run this exact matchup right now
Send the same prompt to Claude Opus 4.8 and Claude Sonnet 4.6 side by side and see the outputs yourself.
Try Claude Opus 4.8 vs Claude Sonnet 4.6 FreeWhat are common questions about Claude Opus 4.8 and Claude Sonnet 4.6?
Is Claude Opus 4.8 cheaper than Claude Sonnet 4.6?
Claude Sonnet 4.6 is cheaper, at $6.00 per million blended tokens vs $10.00 for Claude Opus 4.8.
Which has the bigger context window, Claude Opus 4.8 or Claude Sonnet 4.6?
Claude Opus 4.8 has the larger context window: 500,000 tokens vs 300,000.
Can Claude Opus 4.8 replace Claude Sonnet 4.6 for coding?
Both are viable for coding. Elite coding and multi-step reasoning (Claude Opus 4.8) vs Best intelligence-per-dollar in the Claude lineup (Claude Sonnet 4.6) — pick based on which strength matters more for your workload.
Which is faster, Claude Opus 4.8 or Claude Sonnet 4.6?
Claude Sonnet 4.6 is faster: 76 t/s vs 58 t/s, measured on our speed benchmarks.
Neither of these? See Claude Opus 4.8 alternatives or Claude Sonnet 4.6 alternatives.
What related comparisons help choose between Claude Opus 4.8 and Claude Sonnet 4.6?
Claude Opus 4.8 pricingClaude Sonnet 4.6 pricingvs Claude Opus 4vs DeepSeek V4 Provs Gemini 3.1 Provs Gemini 3.7 FlashPremium model tests
Pricing verified 2026-04-06. Specs verified 2026-08-14.