Anthropic
Claude Opus 4.5
Announced Nov 24, 2025
More capable coding and agents
What could it do?
Anthropic introduced an Opus update focused on software engineering and complex work.
What changed?
Expanded the Claude 4.5 family.
A stronger option for demanding tasks in Claude and the API.
Where it fell short
Reported evaluation results depend on reasoning effort and the agent setup.
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 logBenchmark results
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 4.0One 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, 2026Only mini-SWE-agent v2.0.0 submissions, one run per model. Reasoning effort varies and is labelled. These are published submissions, not a rerun by Leapscope. Latest included release: February 5, 2026; latest run: February 26, 2026.
Source: SWE bench Verified ↗Download selected resultsChecked Oct 8, 2026