GPT-5vsGPT-5.3-Codex
GPT-5 | GPT-5.3-Codex | |
|---|---|---|
| API pricingUSD per 1M tokens · lower wins | ||
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it. | $1.25 | $1.75 |
Output priceWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one. | $10.00 | $14.00 |
Cached input priceA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again. | $0.125 | $0.175 |
Cheapest inputLowest input rate across third-party providers, excluding the lab itself. The cheapest endpoint may run a quantised build or a shorter context — see "Available from" on the model page. | $1.25Azure | $1.75Azure |
Cheapest outputLowest output rate across third-party providers, excluding the lab itself. May come from a different provider than the cheapest input. | $10.00Azure | $14.00Azure |
| Benchmarks | ||
BullshitBench v2Nonsense detection — Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | 21% | 24% |
| BenchmarksPublished by one model only | ||
SWE-Bench VerifiedCoding — Real coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | — | 85% |
Next.js EvalsNext.js coding — Vercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better. | — | 81% |
| Overview | ||
| Company | OpenAI | OpenAI |
| Release date | Aug 7 2025 | Feb 5 2026 |
| Access | Proprietary | Proprietary |
Other comparisons
Frequently asked questions
GPT-5.3-Codex leads GPT-5 on 1 of the 1 benchmark they both report (BullshitBench v2). GPT-5 is cheaper on both input and output: $1.25 vs $1.75 per million input tokens, and $10.00 vs $14.00 per million output tokens. GPT-5 shipped 182 days before GPT-5.3-Codex, so benchmark comparisons should account for the intervening progress.
Published specifications for these two models are limited — see each model page for the latest details.
On BullshitBench v2, GPT-5.3-Codex leads at 24% vs GPT-5 at 21%.
GPT-5 was released by OpenAI on Aug 7 2025.
GPT-5.3-Codex was released by OpenAI on Feb 5 2026.
GPT-5 is cheaper on both input and output: $1.25 vs $1.75 per million input tokens, and $10.00 vs $14.00 per million output tokens. Rates are pay-as-you-go API prices verified on August 18, 2026.