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Claude Sonnet 4.6 vs GPT-5.3-Codex-Spark

2 vs 0 benchmarks won

Anthropic
Claude Sonnet 4.6
OpenAI
GPT-5.3-Codex-Spark
Overview
CompanyAnthropicOpenAI
Release dateFeb 17 2026Feb 12 2026
Model type
Open sourceNoNo
Specifications
Parameters
Context window
128k
Benchmarks
Science reasoning
GPQA Diamond
89.9%
Software engineering
SWE-Bench Verified
79.6%
Multimodal understanding
MMMU
Timeline
Release gapGPT-5.3-Codex-Spark shipped 5 days before Claude Sonnet 4.6

Which is better: Claude Sonnet 4.6 or GPT-5.3-Codex-Spark?

Claude Sonnet 4.6 leads GPT-5.3-Codex-Spark on 2 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). GPT-5.3-Codex-Spark shipped 5 days before Claude Sonnet 4.6, 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.

Direct benchmark comparisons are unavailable — at least one of these models has not published scores on GPQA Diamond, SWE-Bench Verified, or MMMU.

Frequently asked questions

When was Claude Sonnet 4.6 released?
Claude Sonnet 4.6 was released by Anthropic on Feb 17 2026.
When was GPT-5.3-Codex-Spark released?
GPT-5.3-Codex-Spark was released by OpenAI on Feb 12 2026.

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