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Claude Opus 5 alternatives

Match · Updated July 2026

The closest alternative to Claude Opus 5 is Claude Opus 5 (Fast) — comparable intelligence (— vs —); for a cheaper option, Kimi K3 runs $3.00/M vs $5.00/M; for more speed, Gemini 2.5 Flash Lite hits 166 t/s; and the best open-weight substitute is GLM 5.2.

Frequently asked

What is the best alternative to Claude Opus 5?

Claude Opus 5 (Fast) is the closest alternative to Claude Opus 5, with an Intelligence Index of — (Claude Opus 5 scores —) at $10.00 per million input tokens.

Is there a cheaper alternative to Claude Opus 5?

Yes — Kimi K3 costs $3.00 per million input tokens versus $5.00 for Claude Opus 5, while staying within ~8 points of its Intelligence Index.

Is there an open-source alternative to Claude Opus 5?

GLM 5.2 is the strongest open-weight alternative to Claude Opus 5 — downloadable from Hugging Face and self-hostable, scoring 51.1 on intelligence.