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Comparison · 2 models · Updated Oct 4, 2026

GPT-5.3 Codex vs GPT-5.2

GPT-5.3 Codex comes out ahead, 64 to 61 on our weighted score.

  1. Our pick

    OpenAI

    GPT-5.3 Codex

    Released Feb 5, 2026

    64/100
    • ECI156.8
    • Price$1.75 / $14.00
    • Context400K
    Full specs Remove GPT-5.3 Codex

  2. OpenAI

    GPT-5.2

    Released Dec 11, 2025

    61/100
    • ECI153.5
    • Price$1.75 / $14.00
    • Context400K
    Full specs Remove GPT-5.2

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

GPT-5.3 Codex is our pick

GPT-5.3 Codex is the better all-round choice, scoring 64/100 against GPT-5.2 (61). It leads on capability and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGPT-5.3 CodexCapabilities Index (ECI): GPT-5.3 Codex 156.8 · GPT-5.2 153.5
  • Lowest priceSame priceGPT-5.3 Codex $4.81 · GPT-5.2 $4.81 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameGPT-5.3 Codex 400,000 · GPT-5.2 400,000 tokens
  • Widest inputsGPT-5.3 CodexGPT-5.3 Codex: Text, Images, PDFs · GPT-5.2: Text, Images
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-5.3 CodexGPT-5.2
CapabilityCapabilities Index (ECI)50%8783
Price25%1818
Inputs & features15%8070
Context window10%4444
Overall100%64/10061/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

GPT-5.3 Codex vs GPT-5.2 specifications side by side
SpecificationGPT-5.3 CodexOpenAIGPT-5.2OpenAI
Capability
Capabilities Index (ECI)156.8 (best)153.5
ECI rank#18 of 148 (best)#38 of 148
GPQA DiamondGraduate-level science questions—91.4%
FrontierMath Tiers 1–3Research-level mathematics—67.4%
OTIS Mock AIME 2024–2025Competition mathematics—96.1%
SWE-bench VerifiedFixing real GitHub issues74.8% (best)73.8%
SimpleQA VerifiedShort factual questions—37.1%
Price per million tokens
Input$1.75$1.75
Output$14.00$14.00
Cached input$0.175$0.175
Blended (3:1)$4.81$4.81
Long-context rateSame rateSame rate
Price sourceOfficial OpenAI APIOfficial OpenAI API
Limits
Context window400,000 tokens400,000 tokens
Max output128,000 tokens128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesNo
AudioNoNo
VideoNoNo
ReasoningYeslow · medium · high · xhighYeslow · medium · high · xhigh
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDgpt-5.3-codexgpt-5.2
API providers1921 (best)
ReleasedFeb 5, 2026Dec 11, 2025
Knowledge cutoffAug 31, 2025Aug 31, 2025
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • GPT-5.3 Codex$45.50
  • GPT-5.2$45.50
04 — Questions

Which should you choose?

Which is better: GPT-5.3 Codex or GPT-5.2?

GPT-5.3 Codex is the better all-round choice, scoring 64/100 against GPT-5.2 (61). It leads on capability and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, GPT-5.3 Codex or GPT-5.2?

GPT-5.3 Codex and GPT-5.2 cost the same: $1.75 input / $14.00 output per million tokens.

Which scores higher on benchmarks?

GPT-5.3 Codex scores higher on the Capabilities Index (ECI): GPT-5.3 Codex 156.8 (#18 of 148) and GPT-5.2 153.5 (#38 of 148). The confidence ranges of the top two overlap (153.5–160.8 vs 151.7–155.4), so treat the gap as small. On individual benchmarks: SWE-bench Verified — GPT-5.3 Codex 74.8%, GPT-5.2 73.8%.

Which is better for coding?

GPT-5.3 Codex resolves more real GitHub issues on SWE-bench Verified: GPT-5.3 Codex 74.8% and GPT-5.2 73.8%. Both support tool calling for agent workflows.

Which has the bigger context window?

GPT-5.3 Codex and GPT-5.2 share the same 400,000-token context window. Maximum output per response: GPT-5.3 Codex up to 128,000, GPT-5.2 up to 128,000 tokens.

Which can read images, PDFs, audio or video?

GPT-5.3 Codex accepts text, images and PDFs; GPT-5.2 accepts text and images. GPT-5.3 Codex handles the widest range of inputs.

Are any of these open source?

No. GPT-5.3 Codex and GPT-5.2 are proprietary and only available through APIs and apps.

Which is newer?

GPT-5.3 Codex is the newest, released Feb 5, 2026. GPT-5.2 came out Dec 11, 2025. Knowledge cutoff: GPT-5.3 Codex Aug 31, 2025, GPT-5.2 Aug 31, 2025.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.

05 — Keep comparing

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