Compare documented LLM context and output envelopes
LLM Context Window Comparison — Input, Output, and Usable Token Limits
A larger advertised context window is not automatically a larger usable request envelope or a better long-document model. Separate system, message, tool, media, reasoning, and answer reserves for the exact model snapshot, host, and surface, then fail closed when token accounting cannot join. Rolling aliases and beta limits do not transfer silently. Verified 2026-09-02.
Verified 2026-09-02 — source
Compare documented input and output envelopes while preserving exact model, host, surface, tokenizer, and alias identity. Qualitative demand: dedicated current context-window tables were reviewed 2026-09-02; exact US monthly volume is unavailable.
Evidence boards · verified 2026-09-02
Intent answer: A larger advertised context window is not automatically a larger usable request envelope or a better long-document model. Separate system, message, tool, media, reasoning, and answer reserves for the exact model snapshot, host, and surface, then fail closed when token accounting cannot join. Rolling aliases and beta limits do not transfer silently. Verified 2026-09-02.
Demand evidence: Qualitative demand: dedicated current context-window tables were reviewed 2026-09-02; exact US monthly volume is unavailable.
Scope boundary: Compare documented input and output envelopes while preserving exact model, host, surface, tokenizer, and alias identity. Exact provider, seller, serving host, account/tier, endpoint, model/snapshot, region, feature, and evidence identity are required; unresolved joins render Unavailable.
Context-and-output contract normalizer
Deterministic formula / rule: comparable envelope = exact model/snapshot/host/surface + context definition + input/output values + unit/tokenizer evidence.
Boundary: Owns documented cross-model envelopes; it cannot turn marketing language, bytes, words, or sibling-model limits into tokens.
| Frozen scenario | Exact identity and evidence fields | Result | State |
|---|---|---|---|
| combined-window | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=combined-window; model/snapshot/host/surface; context definition; max input/output/combined; prerequisite; unit/tokenizer; source/date; unavailable state; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 1 rule is reproducible but no production observation is claimed |
| input-only cap | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=input-only cap; model/snapshot/host/surface; context definition; max input/output/combined; prerequisite; unit/tokenizer; source/date; unavailable state; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 1 rule is reproducible but no production observation is claimed |
| separate output cap | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=separate output cap; model/snapshot/host/surface; context definition; max input/output/combined; prerequisite; unit/tokenizer; source/date; unavailable state; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 1 rule is reproducible but no production observation is claimed |
| long-context beta/tier | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=long-context beta/tier; model/snapshot/host/surface; context definition; max input/output/combined; prerequisite; unit/tokenizer; source/date; unavailable state; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 1 rule is reproducible but no production observation is claimed |
| modality-specific limit | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=modality-specific limit; model/snapshot/host/surface; context definition; max input/output/combined; prerequisite; unit/tokenizer; source/date; unavailable state; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 1 rule is reproducible but no production observation is claimed |
| undocumented accounting | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=undocumented accounting; model/snapshot/host/surface; context definition; max input/output/combined; prerequisite; unit/tokenizer; source/date; unavailable state; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — exact context-windows evidence join is not closed for “undocumented accounting” | FAIL CLOSED — manual, probe, or source evidence required |
First-party citation: OpenAI model documentation. Verified 2026-09-02; missing or conflicting joins fail closed.
Usable-envelope compiler
Deterministic formula / rule: usable = system + messages + retrieved/media + tool schema/results + reasoning allowance + answer reserve; admit only when total ≤ documented cap.
Boundary: Owns capacity accounting, not quality, retrieval, price, or long-document recommendations.
| Frozen scenario | Exact identity and evidence fields | Result | State |
|---|---|---|---|
| 8K chat | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=8K chat; component token fields; total; documented cap; reserve; admitted/conditional/blocked result; missing-component Unavailable; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 2 rule is reproducible but no production observation is claimed |
| 128K repository | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=128K repository; component token fields; total; documented cap; reserve; admitted/conditional/blocked result; missing-component Unavailable; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 2 rule is reproducible but no production observation is claimed |
| 512K corpus | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=512K corpus; component token fields; total; documented cap; reserve; admitted/conditional/blocked result; missing-component Unavailable; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 2 rule is reproducible but no production observation is claimed |
| 1M corpus | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=1M corpus; component token fields; total; documented cap; reserve; admitted/conditional/blocked result; missing-component Unavailable; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 2 rule is reproducible but no production observation is claimed |
| image-plus-tools request | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=image-plus-tools request; component token fields; total; documented cap; reserve; admitted/conditional/blocked result; missing-component Unavailable; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 2 rule is reproducible but no production observation is claimed |
| long reasoning with 40K answer | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=long reasoning with 40K answer; component token fields; total; documented cap; reserve; admitted/conditional/blocked result; missing-component Unavailable; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 2 rule is reproducible but no production observation is claimed |
First-party citation: Anthropic Messages API. Verified 2026-09-02; missing or conflicting joins fail closed.
Limit-identity and drift ledger
Deterministic formula / rule: transfer = requested ID = effective ID + same host/surface/interval + compatible cap evidence; otherwise no numeric inheritance.
Boundary: Owns alias and limit drift; retired or preview identities cannot be used to rewrite a current model verdict.
| Frozen scenario | Exact identity and evidence fields | Result | State |
|---|---|---|---|
| rolling alias | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=rolling alias; requested/effective IDs; provider/host; prior/current evidence; interval; changed field; transfer eligibility; dependent pages; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — exact context-windows evidence join is not closed for “rolling alias” | FAIL CLOSED — manual, probe, or source evidence required |
| dated snapshot | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=dated snapshot; requested/effective IDs; provider/host; prior/current evidence; interval; changed field; transfer eligibility; dependent pages; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 3 rule is reproducible but no production observation is claimed |
| alternate host | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=alternate host; requested/effective IDs; provider/host; prior/current evidence; interval; changed field; transfer eligibility; dependent pages; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 3 rule is reproducible but no production observation is claimed |
| preview/GA surface | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=preview/GA surface; requested/effective IDs; provider/host; prior/current evidence; interval; changed field; transfer eligibility; dependent pages; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 3 rule is reproducible but no production observation is claimed |
| batch-specific cap | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=batch-specific cap; requested/effective IDs; provider/host; prior/current evidence; interval; changed field; transfer eligibility; dependent pages; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 3 rule is reproducible but no production observation is claimed |
| retired model | route=/compare/llm-context-windows; owner=context-windows; provider/seller/host/account/tier/endpoint/model/snapshot/region/feature/request=context-windows; scenario=retired model; requested/effective IDs; provider/host; prior/current evidence; interval; changed field; transfer eligibility; dependent pages; observed versus documented versus assumed inputs are labeled; artifact/schema/tool/job/result hashes and verification date=2026-09-02 | Unavailable — frozen context-windows fixture requires an exact source, identity, and result receipt | UNTESTED — module 3 rule is reproducible but no production observation is claimed |
First-party citation: Google Gemini API model documentation. Verified 2026-09-02; missing or conflicting joins fail closed.
Method and limitations: this board exposes deterministic rules, first-party citations, and dated evidence identities. It does not invent volume, coverage, entitlement, retention, residency, quota, capacity, feature support, quality, price, reliability, or legal conclusions. Run the context-windows evidence flow →