BenchLeader

GPT-5.3-Codex

Reasoning effort

GPT-5.3-Codex is an OpenAI proprietary reasoning model, released 5 Feb 2026. Its best configuration (xhigh reasoning effort) ranks #60 of 785 on the BenchLeader Index at 63.8 ±4.9, in the upper half. The ± is the point: 153 other configurations score within that range, so they and this one cannot be told apart on quality alone — price and speed are what separate them. It scores highest in agents & tools (80) and lowest in coding (61). At $4.81 per million tokens blended it is among the most expensive ranked models. Output speed of 84 tokens per second puts it slower than most, with a first answer in 60.6 s. It has been measured at 3 reasoning-effort settings; this summary describes the best-scoring one, and the tabs above switch between them. Last measured 20 Oct 2026.

Blended price
$4.81/M
$1.75 in · $14.00 out
Output speed
84 tok/s
measured by Artificial Analysis
First answer
61 s
first token 2.20 s
Context
400k
Full answer
67 s
median, reasoning included
Cost per run
–
Released
5 Feb 2026
How it scores by categoryDashed line = average model (50). One step of 15 = one standard deviation.
  1. Overall index64
  2. Reasoning69
  3. Coding61
  4. Agents & tools80
  5. Knowledge66
  6. Instruction following74
  7. Multimodal62
  8. Long context67
  9. Composite66

Versions

OpenAI has shipped 5 models under this name. Each is ranked on its own results; a newer version often has fewer results so far, which holds its index nearer the average until more arrive.

ModelReleasedIndexRank
GPT-5.3-Codexxhighthis page5 Feb 202663.8#60
GPT-5.2-Codexxhigh18 Dec 202559.4#133
GPT-5.1-Codexhigh12 Nov 202556.3#208
GPT-5-Codexhigh15 Sept 202557.5#177
GPT 5.5 Codex–––

Reasoning-effort configurations

The same model behaves differently depending on how much it is allowed to think. Each row is one setting, scored only on the benchmarks that were run at that setting. “Not stated” collects results from publishers that did not say which setting they used; for a reasoning model that is usually its thinking mode, but we do not assume it. Pick a setting here or at the top of the page to see its price, speed and category scores.

EffortIndexRankSpeedFirst answerChat reply costCategories
high––70 tok/s2.20 s$0.0049Coding 56
xhighbest63.8#6084 tok/s61 s$0.0049Agents & tools 80 · Coding 61 · Composite 66 · Instruction following 74 · Knowledge 66 · Long context 67 · Multimodal 62 · Reasoning 69
not stated––70 tok/s2.20 s$0.0049Agents & tools 58 · Coding 53

How its index has moved

19 Sept 2026 to 23 Oct 2026
596570

The index is recomputed from scratch every day, so a line moves when a new benchmark result lands, when a publisher revises a score, or when the models it is normalised against change. Early movement usually means the score is still settling.

Benchmark results

See all LLM benchmarks. One column per reasoning effort. Rank is among every configuration of every model on that benchmark. Hover a score for the run it came from.

Reasoning

BenchmarkxhighSourceTrend
GPQA Diamond (AA)not in index91.5%#46Artificial Analysis
Humanity's Last Exam (AA)not in index42.5%#68Artificial Analysis
CritPt16.9%#82Artificial Analysis

Coding

Benchmarkhighxhighnot statedSourceTrend
SWE-bench Verified (Epoch)74.8%#15––Epoch AI Benchmarking Hub
WeirdML–77.9%#2279.3%#19WeirdML
Arena WebDeveffort not stated––1407#86Arena (LMArena)
LiveCodeBench–87.3%#15–Vals AI
IOI–53.8%#21–Vals AI
SWE-bench (Vals)not in index–78.0%#33–Vals AI
Vibe Code Bench v1.1not in index–61.8%#52–Vals AI
ALE-Benchnot in index–1655.2#16–Epoch AI Benchmarking Hub

Agents & tools

Benchmarkhighxhighnot statedSourceTrend
Terminal-Bencheffort not stated––78.4%#6Terminal-Bench
Terminal-Bench Hard–53.0%#17–Artificial Analysis
τ²-Bench Telecom (AA)not in index–86.0%#92–Artificial Analysis
HiL-Bencheffort not stated––4.3%#30Scale AI SEAL
Terminal-Bench 2.0 (Vals)not in index64.0%#6––Vals AI
METR Time Horizonsnot in indexeffort not stated––74.5%#6METR
Vending-Bench 2not in indexeffort not stated––5940.1#22Andon Labs

Instruction following

BenchmarkxhighSourceTrend
IFBench75.4%#33Artificial Analysis

Multimodal

BenchmarkxhighSourceTrend
MMMU-Pro78.5%#73Artificial Analysis

Long context

BenchmarkxhighSourceTrend
AA-LCR83.3%#21Artificial Analysis

Composite

Benchmarkxhighnot statedSourceTrend
Epoch Capabilities Indexnot in indexeffort not stated–157.1#24Epoch AI Benchmarking Hub
AA Intelligence Index v4.3.232.5#111–Artificial Analysis

Where to run it

Every provider serving this model through OpenRouter, with throughput and first-token latency measured on live traffic over the last 30 minutes and each provider’s own price. Purple marks the best in each column.

ProviderSpeedFirst tokenInput $/MOutput $/MContextQuantisation
OpenAI76 tok/s1.95 s$1.75$14.00400k–
Azure41 tok/s1.87 s$1.75$14.00400k–

What a task costs

Estimates from list price, output speed and time to first answer for the best configuration. “With caching” assumes three-quarters of the input is served from the prompt cache at $0.175 per 1M. Reasoning tokens are not modelled.

WorkloadTokens in / outCostWith cachingTime
Chat reply400 / 300$0.0049$0.00441.1 min
Summarize a 30-page report12,000 / 600$0.029$0.0151.1 min
Code edit6,000 / 1,500$0.032$0.0241.3 min
Agentic coding session60,000 / 4,000$0.161$0.0901.8 min
Structured extraction2,000 / 200$0.0063$0.00391.1 min

More from OpenAI

New this month

Compare GPT-5.3-Codex with…

See also

Questions people ask

What are GPT-5.3-Codex's benchmark scores?
As of 24 Oct 2026, GPT-5.3-Codex (xhigh effort) scores 63.8 ±4.9 on the BenchLeader Index, top 100, strongest in agents & tools (80) and weakest in coding (61). That rests on 10 independent benchmark results, and every score on this page links to its publisher.
How does GPT-5.3-Codex rank?
GPT-5.3-Codex (xhigh effort) is #60 of 785 ranked configurations on 24 Oct 2026 (top 100). 153 other configurations score within its margin, so the exact position matters less than the band. The leader is Claude Opus 5.5 (max effort) at 72.6.
How much does GPT-5.3-Codex cost per 1M tokens?
As of 24 Oct 2026, GPT-5.3-Codex costs $1.75 per 1M input tokens and $14.00 per 1M output tokens, $4.81 blended (three input tokens per output token).
Is GPT-5.3-Codex better than Grok 4.7?
As of 24 Oct 2026, GPT-5.3-Codex (xhigh) and Grok 4.7 (high) are neck and neck on quality (63.8 vs 63.9 on the BenchLeader Index, inside the ±8.8 margin of error), and Grok 4.7 (high) costs 1.6× less, which makes it the better buy for most workloads. The head-to-head page has the benchmark-by-benchmark detail.
When was GPT-5.3-Codex released?
OpenAI released GPT-5.3-Codex on 5 Feb 2026. BenchLeader has results for it at 3 reasoning-effort settings.

Data as of 24 Oct 2026. Compare these configurations.

Cite as: BenchLeader, “GPT-5.3-Codex: benchmarks, pricing, speed and rank”, data as of 24 Oct 2026, https://www.benchleader.com/models/gpt-5-3-codex.