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Head-to-head comparison

Gemma 4 31B vs GPT-5.3-Codex

Gemma 4 31B (Google) and GPT-5.3-Codex (OpenAI) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 17 August 2026

As of 17 August 2026, GPT-5.3-Codex holds the stronger ModelCap Index position (#20 vs #30); Gemma 4 31B is 41.2× cheaper per output token ($0.34/1M vs $14.00/1M); GPT-5.3-Codex offers the longer context window (400K vs 262K tokens); and Gemma 4 31B ships open weights.

Which should you choose?

Choose Gemma 4 31B if…

  • API cost matters — $0.34/1M output tokens against $14.00/1M, about 41.2× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.10/1M against $1.75/1M.
  • you want to self-host: Gemma 4 31B ships open weights while GPT-5.3-Codex is api only.
  • you want provider choice — 16 listed API providers against 2.
  • you want the more recently listed model — Gemma 4 31B was listed 2 April 2026, GPT-5.3-Codex 24 February 2026.

Choose GPT-5.3-Codex if…

  • you want the stronger overall ModelCap Index position — #20 against #30 (66.4 vs 60.0 points).
  • you need the longer context window — 400K tokens against 262K.
  • Artificial Analysis Intelligence Index is your yardstick — 45.5 against 29.7.

Gemma 4 31B vs GPT-5.3-Codex: specs, pricing and context

Specification comparison of Gemma 4 31B and GPT-5.3-Codex
FieldGemma 4 31BGoogleGPT-5.3-CodexOpenAI
ModelCap Index position#30#20
Index score60.066.4
EvidenceMeasuredMeasured
Input price / 1M tokens$0.10$1.75
Output price / 1M tokens$0.34$14.00
Context window262K tokens400K tokens
Max output tokens262K128K
API providers listed162
Weight accessOpen weightsAPI only
Input modalitiesImage, Text, VideoText, Image, File
First listed2 April 202624 February 2026
PublisherGoogleOpenAI

Evidence: 4 public benchmark observations across 4 boards · 1 public benchmark observation across 1 board. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Gemma 4 31B vs GPT-5.3-Codex

Public benchmark boards where Gemma 4 31B or GPT-5.3-Codex has a published result
BoardGemma 4 31BGPT-5.3-CodexLeads
Arena codingArena (LMArena)14991483–1514—Only one result
LMArena AgentLMArena-18.9%-21.7%–-16.0%—Only one result
Artificial Analysis Intelligence IndexArtificial Analysis29.7intelligence-index45.5intelligence-indexGPT-5.3-Codex

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

Gemma 4 31B vs GPT-5.3-Codex: common questions

Is Gemma 4 31B better than GPT-5.3-Codex?

GPT-5.3-Codex ranks higher on the ModelCap Index as of 17 August 2026: #20 against #30. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it.

Is Gemma 4 31B cheaper than GPT-5.3-Codex?

Gemma 4 31B is cheaper on output tokens: $0.34/1M against $14.00/1M. Input tokens are $0.10/1M for Gemma 4 31B and $1.75/1M for GPT-5.3-Codex. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.

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

GPT-5.3-Codex has the larger context window: 400K tokens against 262K.

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

The two models do not share a coding benchmark board on ModelCap yet, so no head-to-head coding score is published; the ModelCap Index position is the closest overall signal.

Are Gemma 4 31B and GPT-5.3-Codex open-weight models?

Gemma 4 31B: Open weights. GPT-5.3-Codex: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run Gemma 4 31B and GPT-5.3-Codex?

ModelCap currently lists 16 API providers for Gemma 4 31B and 2 for GPT-5.3-Codex, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Gemma 4 31B vs GPT-5.3-Codex comparison?

Every figure comes from the sealed ModelCap dataset published 17 August 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

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