MODEL PROOF
GPT-5.3-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, file
- Output modalities
- text
- Published input price
- $1.75 / 1M tokens
- Published output price
- $14.00 / 1M tokens
- Pricing kind
- fixed
Inspect complete billing conditions and endpoint terms below.
Price from OpenAI: 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 | $1.75/M |
|---|---|
| Output | $14.00/M |
| Cached input | $0.175/M |
| Cache write | Unknown/M |
| Cache write 1h | Unknown/M |
| Reasoning | Unknown/M |
| Web search | $0.01/call |
| Batch discount | 50% |
Who sells it
The same weights, different shops. Cheapest is not like-for-like when serving precision differs.
3 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
| $1.75 | $14.00 | undeclared | 99.99% |
| OpenAIopenai Endpoint terms
| $1.75 | $14.00 | undeclared | 100.00% |
| OpenAIopenai/fast Endpoint terms
| $3.50 | $28.00 | undeclared | — |
Independent scores
No independent benchmark has measured this model. Unrated is not a score of zero.
Best rankings by task
- Godot games #27 1124
- Native Android apps #30 1084
- ASCII art #38 1162
- Web apps #39 1025
- Full-stack apps #42 981
- Mobile apps #44 1051
- SVG #53 1128
- Game development #62 1174
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, file |
| Tool use | yes |
| Reasoning | optional |
| Open weights | no |
Provenance
| Price source | openrouter.ai |
|---|---|
| Fetched | 2026-10-06 |
| Quality data | unrated |
| Cross-checked | vendor page |
Our take
editorial — not a measurementFor teams using Codex tooling, compare this model with other coding candidates on completed repository tasks. Output-heavy generation and repeated repository context have different cost profiles, so inspect both output and cached-input rates in the current table. A coding label is not a substitute for an independent benchmark or a task evaluation.
Strengths
- The accepted source describes a coding-specialised model
- Tool use and cached-input pricing are listed
Weaknesses
- Large generated outputs can dominate a coding workload’s bill
- Check current benchmark coverage before making a measured capability claim
Reach for it when
- Repository-task evaluations in an existing Codex workflow
- Workloads that can measure cache reuse
Avoid it if
- You have not compared completion quality and output volume
- You require downloadable weights
Sources: developers.openai.com
GPT-5.3-Codex is OpenAI’s most advanced agentic coding model, combining the frontier software engineering performance of GPT-5.2-Codex with the broader reasoning and professional knowledge capabilities of GPT-5.2. It achieves state-of-the-art results...
Questions this page answers
What does GPT-5.3-Codex cost?
$1.75/M in, $14.00/M out in this catalogue, as of the fetch date on this page. That is the API row, not a subscription.
Does GPT-5.3-Codex have an independent quality score?
GPT-5.3-Codex has no independent quality score in this catalogue. Unrated is not a score of zero.
What beats GPT-5.3-Codex?
GPT-5.3-Codex has no independent quality score. Unrated is not a score of zero.
Does this page use Artificial Analysis scores for GPT-5.3-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-5.3-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-5.3-codex/)<a href="https://undominated.ai/models/openai__gpt-5.3-codex/"><img src="https://undominated.ai/badge/openai__gpt-5.3-codex.svg" alt="GPT-5.3-Codex — Undominated.ai dominance verdict" height="36"></a>Direct file: https://undominated.ai/badge/openai__gpt-5.3-codex.svg — a static SVG, written by scripts/build-badges.mjs on every build, so the copy you embed is never
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