Composer 1.5vsComposer 2.5

Composer 1.5
Composer 2.5
Benchmarks
Next.js Evals
67%81%
Benchmarks
SWE-Bench Pro
54%
SWE-Bench Multilingual
79.8%
DeepSWE 1.0
18%
Terminal-Bench 2.1
73%
Terminal-Bench 2.0
69.3%
threejseval
1137
Overview
CompanySpaceXAISpaceXAI
Release dateFeb 9 2026May 18 2026
AccessProprietaryProprietary

Other comparisons

Composer 1.5vsClaude Fable 5.1Composer 2.5vsClaude Fable 5.1Composer 1.5vsGPT-6 AstraComposer 2.5vsGPT-6 AstraComposer 1.5vsGemini 3.8 FlashComposer 2.5vsGemini 3.8 FlashComposer 1.5vsMuse Spark 1.3Composer 2.5vsMuse Spark 1.3Composer 1.5vsDeepSeek-V4.1-FlashComposer 2.5vsDeepSeek-V4.1-FlashComposer 1.5vsMistral Medium 3.5Composer 2.5vsMistral Medium 3.5

Frequently asked questions

Composer 2.5 leads Composer 1.5 on 1 of the 1 benchmark they both report (Next.js Evals). Composer 1.5 shipped 98 days before Composer 2.5, 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.

On Next.js Evals, Composer 2.5 leads at 81% vs Composer 1.5 at 67%.