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Data

Gemma 4 31B vs GPT-5.3 Codex

Updated October 6, 2026. Rank says GPT-5.3 Codex is ahead. Price, access, and your workload can each overturn that. Public scores include evidence status and uncertainty.

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Decision reading

GPT-5.3 Codex has the higher public point estimate, 60.85 versus 40.49. Their conditional score ranges do not overlap. These ranges do not establish rank confidence. 2 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.

Model A
Google logo

Google

40.49/100

Estimated · Public rank #126

Conditional range 30.8–50.2

Model B
OpenAI logo

OpenAI

60.85/100

Supported · Public rank #47

90% interval 54.1–67.6

Shared results
2
Gemma 4 31B only
6
GPT-5.3 Codex only
8
Like-for-like categories
1 / 8
Estimated: Gemma 4 31B · Supported: GPT-5.3 Codex. Conditional ranges do not establish rank confidence.How the comparison works

Which one for your work

Recommendations appear only when a shared evidence basis or an explicit operating constraint supports the call. Secondary and unsupported use cases stay disclosed below the initial list.

  • Coding work

    Code generation, repair, and software-engineering tasks

    GPT-5.3 Codex

    GPT-5.3 Codex has the higher public coding point estimate, 55.8 to 33.2, with Supported evidence for both models. The conditional ranges do not establish rank confidence.

    Confidence: limited
  • Long documents

    Prompts that approach the documented context limit

    GPT-5.3 Codex

    GPT-5.3 Codex has the larger documented context window.

    Confidence: documented
Show secondary and unsupported calls
  • Agentic work

    Tool use, computer use, and multi-step task completion

    Not enough matched evidence

    Gemma 4 31B and GPT-5.3 Codex are scored on Estimated evidence for agentic, so the reading is directional rather than like-for-like.

    Confidence: limited
  • Chat turn cost

    1K fresh input + 500 output tokens

    Not enough matched evidence

    A complete comparable API-rate estimate is not available for both models.

    Confidence: listed-rates
  • Cache-heavy agent loop cost

    200K cached + 20K fresh input + 10K output tokens

    Not enough matched evidence

    A complete comparable API-rate estimate is not available for both models.

    Confidence: rate-fallback
  • Repository review cost

    50K fresh input + 3K output tokens

    Not enough matched evidence

    A complete comparable API-rate estimate is not available for both models.

    Confidence: listed-rates

Which one for a specific job

Choose a job from the LLM Selector's task catalog to see the category row it rests on, under the same basis rules as the table below. A directional row stays directional; choosing a job never creates a winner.

The same task catalog as the LLM Selector. Each job names the evidence surface it rests on; nothing here adds a new score.

33.2Gemma 4 31B55.8GPT-5.3 Codex

Like-for-like · BenchAlign v5.8

GPT-5.3 Codex has the higher coding point estimate. Conditional score ranges do not establish rank confidence.

Coding scores combine specific tasks and setups. Match the editor, harness, and effort to your workflow.

Same basis rules as the category table below

What is actually comparable

Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.

3 categories rest on Estimated evidence or different evidence sets. Those rows remain visible for coverage context but do not name a winner.

Shape of the matched evidence

Only shared public evidence is shown. Sparse evidence stays a ruled list rather than being closed into a radar shape.

Too few matched category axes support a radar. The ruled list below shows only shared benchmark results; positions use each benchmark’s normalized display scale when available.

Bars run 0–100 on each benchmark’s normalized display scale

Category results, on a stated basis

Each row shows the public-lane category score for both models: the BenchAlign v5.8 lane for agentic, coding, and knowledge, and the weighted public rows elsewhere, with the same rank each model page reports. A row is like-for-like only when both scores rest on Supported evidence or the same weighted set. Directional and not-comparable rows remain visible, but they never receive a winner.

Coding

Like-for-like
Gemma 4 31B
33.2
Supported · #85/144
GPT-5.3 Codex
55.8
Supported · #28/144
Basis
BenchAlign v5.8 lane · 2 vs 6 public rows
Reading
GPT-5.3 Codex leads · intervals overlap

Agentic

Directional only
Gemma 4 31B
19.1
Estimated · #101/120
GPT-5.3 Codex
55.2
Estimated · #34/120
Basis
BenchAlign v5.8 lane · 1 vs 4 public rows
Reading
Directional only

Knowledge

Directional only
Gemma 4 31B
38.6
Supported · #107/173
GPT-5.3 Codex
64.3
Estimated · #27/173
Basis
BenchAlign v5.8 lane · 4 vs 0 public rows
Reading
Directional only

Instruction following

Directional only
Gemma 4 31B
91.5
#13/125
GPT-5.3 Codex
91.2
#14/125
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Directional only

Reasoning

Not comparable
Gemma 4 31B
70.2
Unranked · 2 rankable rows
GPT-5.3 Codex
79.6
Unranked · 2 rankable rows
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Multimodal

Not comparable
Gemma 4 31B
59.5
#31/49
GPT-5.3 Codex
76.7
Unranked · 1 rankable row
Basis
Provisional lane · 1 vs 0 weighted rows
Reading
Not comparable

Multilingual

Not comparable
Gemma 4 31B
Not ranked
GPT-5.3 Codex
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Math

Not comparable
Gemma 4 31B
Not ranked
GPT-5.3 Codex
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign v5.8) differ from the provisional-lane categories. Unranked scores sit on the provisional lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.

Supported evidence per lane · bars run 0–100Methodology

What each workload costs

Three fixed token mixes turn per-token rates into comparable decisions. Each scenario states context fit and whether cached input had to fall back to the published list-input rate.

Chat turn

1K fresh input + 500 output tokens

Gemma 4 31B
Self-hosted; infrastructure cost varies
Fits in one request
GPT-5.3 Codex
$0.00875
Fits in one request

Gemma 4 31B has no comparable published API token rate.

Repository review

50K fresh input + 3K output tokens

Gemma 4 31B
Self-hosted; infrastructure cost varies
Fits in one request
GPT-5.3 Codex
$0.1295
Fits in one request

Gemma 4 31B has no comparable published API token rate.

Cache-heavy agent loop

200K cached + 20K fresh input + 10K output tokens

Gemma 4 31B
Self-hosted; infrastructure cost varies
Fits in one request
Cached-input rate unavailable
GPT-5.3 Codex
$0.525
Fits in one request
Cached input priced at the published list-input rate

GPT-5.3 Codex has no published cached-input rate, so cached tokens use its listed input rate. Gemma 4 31B has no comparable published API token rate.

Cached input falls back to the list input rate only where a cached rate is unpublished

Specification differences

Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.

Cached-input rate

A missing cached-input rate falls back to the listed input rate only in the stated workload estimate.

Gemma 4 31B

No comparable hosted API rate

GPT-5.3 Codex

Not published

Reasoning profile

Gemma 4 31B

Reasoning

GPT-5.3 Codex

Reasoning

Weight access

Gemma 4 31B

Open Weight

GPT-5.3 Codex

Proprietary

License

Gemma 4 31B

Open Weight

GPT-5.3 Codex

Proprietary

Release date

Gemma 4 31B

2026-04-02

GPT-5.3 Codex

2026-02-05

If you already use one of these models

Deployment change
The models list different providers, so authentication, endpoint behavior, limits, and feature support may change.
Quality signal
GPT-5.3 Codex has the higher public point estimate, 60.85 versus 40.49. Their conditional score ranges do not overlap. These ranges do not establish rank confidence.
Workload cost
A complete comparable API-rate estimate is not available for both models.
Context tradeoff
GPT-5.3 Codex has the larger documented window (400K).
Run the same representative tasks against both endpoints before changing production traffic.

Questions

Which is better, Gemma 4 31B or GPT-5.3 Codex?

GPT-5.3 Codex has the higher public point estimate, 60.85 versus 40.49. Their conditional score ranges do not overlap. These ranges do not establish rank confidence. The page therefore keeps the decision tied to the specific documented workload.

Which is better for coding, Gemma 4 31B or GPT-5.3 Codex?

GPT-5.3 Codex has the higher public coding point estimate, 55.8 to 33.2, with Supported evidence for both models. The conditional ranges do not establish rank confidence.

Which is better for agentic tasks, Gemma 4 31B or GPT-5.3 Codex?

GPT-5.3 Codex scores higher for agentic tasks on the public lane, 55.2 to 19.1. Gemma 4 31B and GPT-5.3 Codex are scored on Estimated evidence for agentic tasks, so the reading is directional rather than like-for-like. BenchLM does not name a winner for agentic tasks from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which costs less, Gemma 4 31B or GPT-5.3 Codex?

Both models do not have comparable published API token rates, so this page does not name a universal price winner.

Which has the larger context window, Gemma 4 31B or GPT-5.3 Codex?

GPT-5.3 Codex has the larger documented context window: 400K, compared with 256K.

Self-host vs API cost

Estimates at 50,000 req/day · 1000 tokens/req average.

Gemma 4 31B
API / mo$0
Self-host / mo$429
Break-even—
GPT-5.3 Codex
API / mo$11,813
Self-host / moNot listed
Break-even—
Proprietary model — self-hosting not applicable.
Model the full break-even

Benchmark evidence

The full public result ledger is available for audit without forcing a wide desktop table onto a phone.

Browse raw public benchmark evidence16 rows

Agentic

  • Gemma 4 31B35.26%
    GPT-5.3 Codex57.47%

    GPT-5.3 Codex leads this result

  • Terminal-Bench 2.0

    Gemma 4 31B—
    GPT-5.3 Codex77.3%
    Source

    Not directly comparable

  • OSWorld-Verified

    Gemma 4 31B—
    GPT-5.3 Codex64.7%
    Source

    Not directly comparable

  • JobBench

    Gemma 4 31B—
    GPT-5.3 Codex33.7%
    Source

    Not directly comparable

Coding

  • SWE-Rebench

    Gemma 4 31B41.6%
    Source
    GPT-5.3 Codex58.2%
    Source

    GPT-5.3 Codex leads this result

  • React Native Evals

    Gemma 4 31B75.2%
    Source
    GPT-5.3 Codex—

    Not directly comparable

  • SWE-bench Verified

    Gemma 4 31B—
    GPT-5.3 Codex85%
    Source

    Not directly comparable

  • SWE-bench Pro

    Gemma 4 31B—
    GPT-5.3 Codex56.8%
    Source

    Not directly comparable

  • Vibe Code Bench

    Gemma 4 31B—
    GPT-5.3 Codex61.77%
    Source

    Not directly comparable

  • LiveCodeBench (Vals)

    Gemma 4 31B—
    GPT-5.3 Codex87.3%
    Source

    Not directly comparable

  • SWE-bench (Vals)

    Gemma 4 31B—
    GPT-5.3 Codex78.0%
    Source

    Not directly comparable

Multimodal

  • MMMU-Pro

    Gemma 4 31B76.9%
    Source
    GPT-5.3 Codex—

    Not directly comparable

Knowledge

  • GPQA

    Gemma 4 31B84.3%
    Source
    GPT-5.3 Codex—

    Not directly comparable

  • MMLU-Pro

    Gemma 4 31B85.2%
    Source
    GPT-5.3 Codex—

    Not directly comparable

  • HLE

    Gemma 4 31B26.5%
    Source
    GPT-5.3 Codex—

    Not directly comparable

  • HLE w/o tools

    Gemma 4 31B19.5%
    Source
    GPT-5.3 Codex—

    Not directly comparable

16 public results · 2 shared

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Last updated October 6, 2026