Compare GPT-5.6 Sol and GPT-5.6 Terra: Premier Deep Logic vs Scalable Workhorse
GPT-5.6 Sol vs GPT-5.6 Terra: which should I use?
Choose GPT-5.6 Sol only when a matched-effort workload clears its acceptance floor and Terra does not. Use Terra as the balanced default where evidence is comparable and the quality margin is unproven. This receipt is verified 2026-09-01; unsupported effort, retry, latency, and ultra-API joins remain Unavailable.
Verified 2026-09-01
Where can you find price, speed, and task evidence for GPT-5.6 Sol and GPT-5.6 Terra?
Which tasks fit GPT-5.6 Sol and GPT-5.6 Terra?
Best-fit task signals from the published model strengths; this is not a substitute for a controlled benchmark.
| Fact | GPT-5.6 Sol | GPT-5.6 Terra |
|---|---|---|
| Best fit | Legacy GPT-5.6 flagship workloads superseded by GPT-6 Sol. | Legacy GPT-5.6 balanced-tier workloads superseded by GPT-6 Sol. |
| Reasoning mode | Available | Available |
What does a Coding Agent workload cost with GPT-5.6 Sol and GPT-5.6 Terra?
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 | GPT-5.6 Sol | GPT-5.6 Terra |
|---|---|---|
| Coding Agent / task | $0.12 (modeled) | $0.08 (modeled) (winner) |
| Input / output rate | $4.00 / $20.00 per M | $2.50 / $15.00 per M |
How fast are GPT-5.6 Sol and GPT-5.6 Terra?
Only non-estimated benchmark results are shown as measured.
| Fact | GPT-5.6 Sol | GPT-5.6 Terra |
|---|---|---|
| Measured throughput | 44 tokens/s | 78 tokens/s (winner) |
| Time to first token | 560 ms | 380 ms |
How compatible are GPT-5.6 Sol and GPT-5.6 Terra with APIs?
Provider-level wire-format and SDK facts; model-specific parameter differences may still apply.
| Fact | GPT-5.6 Sol | GPT-5.6 Terra |
|---|---|---|
| OpenAI SDK | Usable | Usable |
| Request shape | Canonical /chat/completions and /responses shape — every OpenAI-compatible provider on this site imitates it. | Canonical /chat/completions and /responses shape — every OpenAI-compatible provider on this site imitates it. |
| Streaming | SSE (OpenAI delta) | SSE (OpenAI delta) |
What are the privacy and retention policies for GPT-5.6 Sol and GPT-5.6 Terra?
Provider policy and residency facts from the verified provider registry. A missing retention policy is not treated as a guarantee.
| Fact | GPT-5.6 Sol | GPT-5.6 Terra |
|---|---|---|
| Provider says API data trains models | No | No |
| Published retention period | Unavailable | Unavailable |
| Data residency | US by default; EU data residency available on enterprise agreements | US by default; EU data residency available on enterprise agreements |
How much effort does it take to migrate between GPT-5.6 Sol and GPT-5.6 Terra?
Direction is from each displayed model to the other. Effort is derived from provider compatibility and published parameter maps.
| Fact | GPT-5.6 Sol | GPT-5.6 Terra |
|---|---|---|
| Move GPT-5.6 Sol → GPT-5.6 Terra | drop-in; 0 breaking parameter differences | Target: GPT-5.6 Terra |
| Move GPT-5.6 Terra → GPT-5.6 Sol | Source: GPT-5.6 Terra | drop-in; 0 breaking parameter differences |
| Why | Same provider; only the model identifier changes. | Same provider; only the model identifier changes. |
Exact-pair decision and evidence guide. Verified 2026-09-01. These three sections are computed from dated scenarios; assumptions and unavailable joins are not observations.
Exact pair boundary: requested models are gpt-5-6-sol and gpt-5-6-terra. A broad provider, pricing, task, or rate-limit verdict is out of scope.
Matched-effort Sol/Terra capability receipt
Frozen fixture board. Formula / decision rule: pass = exact model + same effort + required tools/modality + evidence >= acceptance floor; otherwise Unavailable Boundary: Different efforts are never treated as a model-only delta; the broad task verdict remains with task pages.
| Frozen fixture | Joined fields and evidence | Output | State |
|---|---|---|---|
| medium professional analysis | provider=OpenAI; host=api.openai.com; requested=gpt-5.6-sol / gpt-5.6-terra; effort=medium; evidence=2026-09-01 | evidence rows=Unresolved without matched benchmark/version/judge; acceptance=Unresolved | UNAVAILABLE — comparable evidence join required |
| high repository repair | provider=OpenAI; host=api.openai.com; requested=gpt-5.6-sol / gpt-5.6-terra; effort=high; tools=repository; schema=patch+tests; evidence=2026-09-01 | pass only if both sides share repository, tool, and test evidence; current result=Unavailable | UNAVAILABLE — paired tool-run evidence required |
| xhigh agent planning | provider=OpenAI; host=api.openai.com; requested=gpt-5.6-sol / gpt-5.6-terra; effort=xhigh; tools=declared; side_effects=read-only; evidence=2026-09-01 | do not compare Terra medium with Sol xhigh; same-setting result=Unavailable | FAIL CLOSED — effort mismatch prohibited |
| max constraint reasoning | provider=OpenAI; host=api.openai.com; requested=gpt-5.6-sol / gpt-5.6-terra; effort=max; prompt=constraint; judge=human; evidence=2026-09-01 | acceptance floor and denominator are not joined for both exact IDs | UNAVAILABLE — acceptance denominator missing |
| long-context synthesis | provider=OpenAI; host=api.openai.com; requested=gpt-5.6-sol / gpt-5.6-terra; effort=medium; input=long-context; output reserve=declared; evidence=2026-09-01 | context admission can be checked only after both exact model ceilings and accounting join | UNAVAILABLE — context join required |
| unsupported ultra-API fixture | provider=OpenAI; host=api.openai.com; requested=gpt-5.6-sol / gpt-5.6-terra; effort=ultra-api; control=undocumented; evidence=2026-09-01 | ultra-api is not a documented effort value; no capability verdict | UNSUPPORTED — control not admitted |
Provenance: gpt-5-6-sol-vs-gpt-5-6-terra, first-party evidence, surface verification date 2026-09-01. OpenAI GPT-5.6 lineup documentation. Missing joins fail closed.
Quality-floor bilateral admission board
Frozen fixture board. Formula / decision rule: eligible = evidence covers required dimension AND measured value >= floor; lower-cost eligible tier wins; else No supported verdict Boundary: This is a pair-specific threshold board, not a universal coding, research, or finance ranking.
| Frozen fixture | Joined fields and evidence | Output | State |
|---|---|---|---|
| routine copy | workload=routine-copy; consequence=low; review=human spot-check; floor=style+factuality; Sol/Terra coverage=Unresolved | lower-cost eligible tier=Unavailable until both quality cells join | NO SUPPORTED VERDICT — coverage gap |
| supervised coding | workload=supervised-coding; consequence=medium; review=human; floor=tests pass; evidence=local run required | admit the cheaper tier only after paired test evidence clears floor | CONDITIONAL — local paired test required |
| autonomous refactor | workload=autonomous-refactor; consequence=high; review=diff+tests; floor=side-effect-free patch | Sol/Terra selection=Unavailable without tool-run and rollback evidence | UNAVAILABLE — autonomous evidence missing |
| finance extraction | workload=finance-extraction; consequence=high; review=human; floor=field agreement; source spans=required | No supported verdict while exact pair coverage is asymmetric | NO SUPPORTED VERDICT — asymmetric evidence |
| research synthesis | workload=research-synthesis; consequence=medium; review=citation check; floor=source fidelity | choose only the tier with paired source-fidelity evidence; current state=Unavailable | UNAVAILABLE — evidence dimension missing |
| high-consequence review | workload=high-consequence-review; consequence=critical; review=expert; floor=domain acceptance+rollback | neither tier is admitted from generic benchmark evidence | NO SUPPORTED VERDICT — expert evidence required |
Provenance: gpt-5-6-sol-vs-gpt-5-6-terra, first-party evidence, surface verification date 2026-09-01. OpenAI model documentation. Missing joins fail closed.
Retry-adjusted Sol/Terra routing ledger
Frozen fixture board. Formula / decision rule: expected cost = sum(attempt probability × input/output rate × tokens); direct Sol changes decision only when avoided escalation cost clears its premium Boundary: Retry and acceptance rates are assumptions unless observed for this exact pair, host, mode, and workload.
| Frozen fixture | Joined fields and evidence | Output | State |
|---|---|---|---|
| no-retry | route=Sol-only or Terra-only; attempts=1; input/output tokens=declared; rates=pricing owners; acceptance_rate=Unavailable | expected cost=Unavailable because acceptance rate is not observed | UNAVAILABLE — no acceptance-rate transfer |
| one Terra retry | route=Terra; attempts=1+retry; retry_probability=assumption; token carry-forward=declared | expected cost=formula applies; numeric result=Unavailable until retry probability is measured | ASSUMPTION ONLY — measure retry rate |
| Terra-then-Sol escalation | route=Terra→Sol; trigger=acceptance failure; attempt_cap=2; cache_isolation=required | expected pair cost=Unavailable; loop stops after Sol and requires human review | CONDITIONAL — escalation trigger must be observed |
| direct Sol | route=Sol; attempts=1; avoided_failure_cost=workload input; Sol premium=pricing join | direct Sol is preferable only when avoided escalation cost > Sol premium | RULE — threshold formula, no verdict |
| cached long prompt | route=Terra→Sol; cache=provider-documented only; cache-read/write rates=dated join | cache-adjusted cost=Unavailable when cache terms or token accounting are missing | UNAVAILABLE — cache isolation/join |
| missing acceptance rate | route=Terra→Sol; acceptance_rate=missing; failure_rate=missing; source date=2026-09-01 | do not infer expected attempts, cost, or reliability | FAIL CLOSED — missing rate |
Provenance: gpt-5-6-sol-vs-gpt-5-6-terra, first-party evidence, surface verification date 2026-09-01. OpenAI API pricing. Missing joins fail closed.
Method and limitations: calculations use only the displayed deterministic rule and visibly labeled assumptions. Missing provider, host, alias, version, effort, tool, modality, benchmark, workload, rate-period, or date joins fail closed. Run this scenario →
Exact-pair decision guide · verified 2026-09-08
Exact pair boundary: OpenAI; same provider, tier escalation, $4.00/$20.00 vs $2.50/$15.00 tariffs, premier reasoning vs balanced workhorse must join. Requested models are gpt-5.6-sol and gpt-5.6-terra. Provider, rate, pricing, and task pages remain fact owners.
Token pricing and tier escalation expenditure 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 workload expenditure modeling.
| Frozen scenario | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
| 10K frontier mathematical proofs | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=10K frontier mathematical proofs; workload; prompt tokens; completion tokens; GPT-5.6 Sol spend; GPT-5.6 Terra spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — 10K frontier mathematical proofs is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| 50K automated code generation passes | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=50K automated code generation passes; workload; prompt tokens; completion tokens; GPT-5.6 Sol spend; GPT-5.6 Terra spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — 50K automated code generation passes is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| 100K dense document analyses | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=100K dense document analyses; workload; prompt tokens; completion tokens; GPT-5.6 Sol spend; GPT-5.6 Terra spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — 100K dense document analyses is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| prompt caching active (50% read discount both) | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=prompt caching active (50% read discount both); workload; prompt tokens; completion tokens; GPT-5.6 Sol spend; GPT-5.6 Terra spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — prompt caching active (50% 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=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=batch processing active (50% both); workload; prompt tokens; completion tokens; GPT-5.6 Sol spend; GPT-5.6 Terra spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; 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=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=unresolved pricing currency; workload; prompt tokens; completion tokens; GPT-5.6 Sol spend; GPT-5.6 Terra spend; budget delta; cost winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; 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: OpenAI API pricing; verification date 2026-09-08. Missing or conflicting joins fail closed.
Two-tier dual-agent architecture and enterprise cost savings
Frozen scenario board. Formula / deterministic rule: blended_spend = terra_volume * terra_cost + sol_escalated_volume * sol_cost Boundary: Owns two-tier architectural routing between cost-efficient Terra and frontier Sol.
| Frozen scenario | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
| 100% GPT-5.6 Terra baseline ($2.50/$15.00) | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=100% GPT-5.6 Terra baseline ($2.50/$15.00); escalation mix; total monthly queries; blended spend; cost savings vs pure Sol; quality retention; router verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — 100% GPT-5.6 Terra baseline ($2.50/$15.00) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| 90% Terra / 10% Sol escalation | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=90% Terra / 10% Sol escalation; escalation mix; total monthly queries; blended spend; cost savings vs pure Sol; quality retention; router verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — 90% Terra / 10% Sol escalation is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| 80% Terra / 20% Sol escalation | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=80% Terra / 20% Sol escalation; escalation mix; total monthly queries; blended spend; cost savings vs pure Sol; quality retention; router verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — 80% Terra / 20% Sol escalation is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| 50% Terra / 50% Sol escalation | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=50% Terra / 50% Sol escalation; escalation mix; total monthly queries; blended spend; cost savings vs pure Sol; quality retention; router verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — 50% Terra / 50% Sol escalation is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| 100% direct GPT-5.6 Sol execution | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=100% direct GPT-5.6 Sol execution; escalation mix; total monthly queries; blended spend; cost savings vs pure Sol; quality retention; router verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — 100% direct GPT-5.6 Sol execution is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| unresolved router confidence threshold | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=unresolved router confidence threshold; escalation mix; total monthly queries; blended spend; cost savings vs pure Sol; quality retention; router verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — unresolved router confidence threshold has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: OpenAI model documentation; verification date 2026-09-08. Missing or conflicting joins fail closed.
Mathematical proof verification and defect prevention ROI
Frozen scenario board. Formula / deterministic rule: roi = prevented_defect_value - tier_escalation_spend; mission-critical defect floor Boundary: Owns mission-critical defect prevention and formal reasoning modeling.
| Frozen scenario | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
| autonomous algorithmic refactoring | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=autonomous algorithmic refactoring; workload domain; Terra pass rate; Sol pass rate; defect reduction; economic ROI; selection verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — autonomous algorithmic refactoring is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| formal mathematical theorem proof | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=formal mathematical theorem proof; workload domain; Terra pass rate; Sol pass rate; defect reduction; economic ROI; selection verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — formal mathematical theorem proof is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| financial risk modeling and compliance | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=financial risk modeling and compliance; workload domain; Terra pass rate; Sol pass rate; defect reduction; economic ROI; selection verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — financial risk modeling and compliance is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| complex JSON schema generation | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=complex JSON schema generation; workload domain; Terra pass rate; Sol pass rate; defect reduction; economic ROI; selection verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — complex JSON schema generation is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| infinite loop circuit breaker trigger | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=infinite loop circuit breaker trigger; workload domain; Terra pass rate; Sol pass rate; defect reduction; economic ROI; selection verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — infinite loop circuit breaker trigger is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
| unresolved evaluation metric | pair=gpt-5.6-sol vs gpt-5.6-terra; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-5.6-sol,gpt-5.6-terra; scenario=unresolved evaluation metric; workload domain; Terra pass rate; Sol pass rate; defect reduction; economic ROI; selection verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-08; measurement versus assumption=explicit | Unavailable — unresolved evaluation metric has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: OpenAI API documentation; verification date 2026-09-08. 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 GPT-5.6 Sol and GPT-5.6 Terra compare on specs?
| GPT-5.6 Sol | GPT-5.6 Terra | |
|---|---|---|
| Price (input) | $4.00/M | $2.50/M ✓ |
| Price (output) | $20.00/M | $15.00/M ✓ |
| Blended price | $8.00/M | $5.63/M ✓ |
| Context window | 1,000,000 tokens | 1,000,000 tokens |
| Max output | 128,000 tokens | 128,000 tokens |
| Modalities | text, vision | text, vision |
| Reasoning mode | Yes | Yes |
| Released | 2026-06 | 2026-06 |
| Speed | 44 t/s | 78 t/s ✓ |
How much do GPT-5.6 Sol and GPT-5.6 Terra cost at scale?
| Tokens / month | GPT-5.6 Sol | GPT-5.6 Terra | Delta |
|---|---|---|---|
| 1,000,000 | $8.00 | $5.63 | $2.38 (1.4×) |
| 10,000,000 | $80.00 | $56.25 | $23.75 (1.4×) |
| 100,000,000 | $800.00 | $562.50 | $237.50 (1.4×) |
Choose GPT-5.6 Sol if…
- ✓Strongest OpenAI 5.6 model for agentic, long-horizon coding
- ✓Deep reasoning mode for multi-step planning
- ✓Native vision input and 1M context
- ✓Legacy GPT-5.6 flagship workloads superseded by GPT-6 Sol.
Choose GPT-5.6 Terra if…
- ✓Balanced cost-to-intelligence ratio
- ✓Reasoning mode available on demand
- ✓Same 1M context as Sol
- ✓Legacy GPT-5.6 balanced-tier workloads superseded by GPT-6 Sol.
Run this exact matchup right now
Send the same prompt to GPT-5.6 Sol and GPT-5.6 Terra side by side and see the outputs yourself.
Try GPT-5.6 Sol vs GPT-5.6 Terra FreeWhat are common questions about GPT-5.6 Sol and GPT-5.6 Terra?
Is GPT-5.6 Sol cheaper than GPT-5.6 Terra?
GPT-5.6 Terra is cheaper, at $5.63 per million blended tokens vs $8.00 for GPT-5.6 Sol.
Which has the bigger context window, GPT-5.6 Sol or GPT-5.6 Terra?
Both models support 1,000,000 tokens of context.
Can GPT-5.6 Sol replace GPT-5.6 Terra for coding?
Both are viable for coding. Strongest OpenAI 5.6 model for agentic, long-horizon coding (GPT-5.6 Sol) vs Balanced cost-to-intelligence ratio (GPT-5.6 Terra) — pick based on which strength matters more for your workload.
Which is faster, GPT-5.6 Sol or GPT-5.6 Terra?
GPT-5.6 Terra is faster: 78 t/s vs 44 t/s, measured on our speed benchmarks.
What related comparisons help choose between GPT-5.6 Sol and GPT-5.6 Terra?
GPT-5.6 Sol pricingGPT-5.6 Terra pricingvs GPT-4ovs DeepSeek V4 Provs Grok 4.3vs Claude Fable 5Premium model tests
Pricing verified 2026-08-14. Specs verified 2026-08-14.