Claude Opus 4.8

by Anthropic

Anthropic’s frontier Opus release between 4.6 and Opus 5 — the model most competitors benchmarked against through mid-2026.

Part of the Claude Opus 4 series.

Timeline

DateEvent
2026-05-24Leaks alongside Sonnet 4.8 and Mythos 1
2026-07Widely available; noted as “acting like Opus 5” in capability
2026-08Displaced in benchmark coverage by Qwen 3.8 Max, Muse Spark 1.2, Ornith 1.5

Notes

Opus 4.8 became the de-facto reference point for “frontier” during summer 2026 — the model
open-weight releases measured themselves against. Coverage is dominated not by Anthropic’s
own launch material but by challengers claiming to match or beat it, usually at far lower cost:
Qwen 3.8 Max, Muse Spark 1.2 (Meta), DeepSeek V4 Flash via OpenCode, and Ornith 1.5.

That pattern is the story: by August 2026 matching Opus 4.8 was table stakes for open-weight
models, and the differentiator had shifted to price and local runnability.