Anthropic

Claude Opus 4.8

Announced May 28, 2026

More consistent longer tasks

What could it do?

Anthropic announced improvements across coding, agents and professional work.

What changed?

An update focused on autonomy.

WHY IT MATTERED

Supported longer workflows.

Where it fell short

Reliability remains task dependent.

Sources checked Oct 7, 2026

Release facts were checked against the sources below. Performance claims belong to the developers; we have not independently tested these models.

Developer announcement or release log

Benchmark results

EPOCH AI CAPABILITY ESTIMATE

158.2index points

Tested variant: Claude Opus 4.8Source interval: 156.0 to 160.8Variant date in source: May 28, 2026

A benchmark estimate, not a percentage or capability multiplier. Reasoning settings are not specified in this source table. Historical estimates can change in later snapshots.

Epoch AI methodology ↗Download the source snapshotChecked Oct 7, 2026 · CC BY 4.0

PUBLISHED BENCHMARK RESULT

1481rating points

Tested: claude-opus-4-8-highText Arena Overall · October 8, 2026Reported interval: 1477 to 148564,177 votes

One explicitly named variant per release. Scores come from the same Overall snapshot; preliminary entries and reported intervals are preserved. These are current ratings of earlier variants, not their launch day ratings.

Source: Text Arena ↗Download selected resultsChecked Oct 8, 2026

Understand the benchmarks Find this release on the chart