Claude Opus 5: Near-Fable Intelligence at Half the Cost

Claude Opus 5 went generally available on July 24, 2026. Per Anthropic's launch announcement, it delivers greatly improved performance for the same cost as its predecessor, Opus 4.8, and gets close to the intelligence of the frontier Claude Fable 5 at substantially lower cost per task. The API identifier is claude-opus-5.

The headline is the price. Opus 5 launched at the identical $5 in / $25 out per MTok that Opus 4.8 charged, so the entire performance gain arrives at zero extra cost. It also ships with adjustable effort: you can push it toward maximum intelligence on a hard story, or dial it down to conserve tokens for faster, cheaper runs on routine work. That flexibility is what makes it a genuine default rather than a top-shelf model you ration.

Data verified July 24, 2026 against Anthropic's launch announcement. Anthropic did not publish a context-window figure at launch, so this page leaves it unstated rather than guessing, freshness and honesty are the whole point of these model pages.

Anthropic's launch numbers are framed as relative claims rather than raw absolute scores, so that is how we report them, attributed and unrounded. Every figure below is Anthropic's own, from the Opus 5 launch materials:

Data verified July 24, 2026. These are vendor claims, not yet reproduced by third parties, so treat them as provisional, as with any launch-day benchmark. Two of the four (CursorBench and OSWorld) are explicitly framed against Fable 5, which is the more interesting comparison and the one we break down next.

This is the easy call. Opus 5 and Opus 4.8 cost the exact same $5 in / $25 out per MTok, and Anthropic reports Opus 5 more than doubling Opus 4.8's Frontier-Bench v0.1 score at a lower cost per task. For new work, there is little reason to keep pinning to Opus 4.8 once Opus 5 is available on your plan.

Fable 5 is Anthropic's Mythos-class frontier model and still tops some benchmarks, but it costs $10 in / $50 out per MTok, twice Opus 5's $5 in / $25 out per MTok. Opus 5's pitch is that you give up very little to save half:

The honest read: for the large majority of agentic coding, Opus 5 is now the value pick, near the frontier at half the price. Reserve Fable 5 for the genuinely hardest work where the last fraction of capability pays for itself. The full breakdown, including cost math, is in Claude Opus 5 vs Claude Fable 5.

Opus 5 is the current Opus in Claude Code, select it the same way you always reached Opus:

/model opus

Fast mode, around 2.5x the default speed at twice the base price, is available through usage credits. If you run agents in parallel, the routing question is where Opus 5 earns its keep: on an AIDEN board each story card launches its own Claude Code session, so you can hand Opus 5 the complex stories, drop to Sonnet or Haiku for mechanical ones, and reserve Fable 5 for the one genuinely brutal refactor. That per-story routing is the whole point of model routing for coding agents.