MODEL PROOF
GPT-5.1-Codex
NOT INDEPENDENTLY RATED
No independent LMArena score is published for this model.
- Independent LMArena score
- Not independently rated
- Context window
- 400K
- Maximum output
- 128K
- Input modalities
- text, image
- Output modalities
- text
- Published input price
- $1.25 / 1M tokens
- Published output price
- $10.00 / 1M tokens
- Pricing kind
- fixed
Inspect complete billing conditions and endpoint terms below.
Price from Azure: the cheapest offer that is serving, at standard delivery and at the maker’s precision or better, at its standard rate.
Every price dimension · USD per million tokens
| Input | $1.25/M |
|---|---|
| Output | $10.00/M |
| Cached input | $0.130/M |
| Cache write | Unknown/M |
| Cache write 1h | Unknown/M |
| Reasoning | Unknown/M |
| Web search | $0.01/call |
Who sells it
The same weights, different shops. Cheapest is not like-for-like when serving precision differs.
1 provider offers · rates, limits and conditions
Rates are USD per million tokens. Endpoint terms can differ even when the quoted price and precision match. A listed parameter is a provider declaration, not a task-success test.
| Seller | Input | Output | Precision | Uptime (1d) |
|---|---|---|---|---|
| Azureazure Endpoint terms
| $1.25 | $10.00 | undeclared | 99.99% |
Independent scores
No independent benchmark has measured this model. Unrated is not a score of zero.
Best rankings by task
- Mobile apps #18 1191
- Full-stack apps #30 1086
- UI components #39 1244
- Web apps #40 1011
- Data visualisation #47 1220
- Game development #70 1151
- Code categories #72 1158
- Websites #76 1168
Per-task Elo and rank from Design Arena, via OpenRouter’s model feed. The rank is the feed’s, and it counts models OpenRouter does not list.
Capability
| Context window | 400K |
|---|---|
| Max output | 128K |
| Input modes | text, image |
| Tool use | yes |
| Reasoning | always on |
| Open weights | no |
Provenance
| Price source | openrouter.ai |
|---|---|
| Fetched | 2026-10-06 |
| Quality data | unrated |
GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....
Questions this page answers
What does GPT-5.1-Codex cost?
$1.25/M in, $10.00/M out in this catalogue, as of the fetch date on this page. That is the API row, not a subscription.
Does GPT-5.1-Codex have an independent quality score?
GPT-5.1-Codex has no independent quality score in this catalogue. Unrated is not a score of zero.
What beats GPT-5.1-Codex?
GPT-5.1-Codex has no independent quality score. Unrated is not a score of zero.
Does this page use Artificial Analysis scores for GPT-5.1-Codex?
No. Artificial Analysis figures are not published here. Quality on this page is LMArena Elo where a score exists; otherwise the row is unrated.
Does a missing score mean GPT-5.1-Codex scored zero?
Unrated is not a score of zero.
MODEL MONUMENT
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The verdict as one SVG, for a README or a docs page. It states this model's dominance status at the balanced workload on the LMArena lens, with the date it was computed, and it is rebuilt with the catalogue — so it changes when the verdict changes, including to one you would rather it did not.
[](https://undominated.ai/models/openai__gpt-5.1-codex/)<a href="https://undominated.ai/models/openai__gpt-5.1-codex/"><img src="https://undominated.ai/badge/openai__gpt-5.1-codex.svg" alt="GPT-5.1-Codex — Undominated.ai dominance verdict" height="36"></a>Direct file: https://undominated.ai/badge/openai__gpt-5.1-codex.svg — a static SVG, written by scripts/build-badges.mjs on every build, so the copy you embed is never
older than the last deploy.
