Anthropic
Claude Haiku 5.5
Announced Oct 7, 2026
Fast assistance for frequent tasks
What could it do?
Anthropic introduced Haiku 5.5 for frequent tasks such as summarizing, classifying information and supporting coding agents.
What changed?
Added adjustable reasoning effort to the Haiku tier.
Teams gained another option for balancing response quality, speed and cost.
Where it fell short
Developer reported capabilities; no comparable score is included in our current Epoch snapshot.
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
No comparable ECI score is available for this release in our source snapshot. Missing scores are never estimated.
Selected highest effort variant where available in the current table. Starred partial results are excluded. Claude fallback configurations can use other models when safeguards intervene.
Source: Artificial Analysis Intelligence Index ↗Download selected resultsChecked Oct 8, 2026