As of: 2026-10-20 02:15 CEST.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/p/x-arcprize-2110417867288039864/

# “Haiku 5.5 from @AnthropicAI on ARC-AGI (Verified): - ARC-AGI-3: 2.8%, $437 (provider…”

ARC Prize (@arcprize), X, 2026-10-14.
Source: https://x.com/arcprize/status/2110417867288039864

## Archived text

> Haiku 5.5 from @AnthropicAI on ARC-AGI (Verified):
> 
> - ARC-AGI-3: 2.8%, $437 (provider adapter harness); 0.5%, $388 (standard harness)
> - ARC-AGI-2: 61.3%, $0.085/task
> - ARC-AGI-1: 89.0%, $0.051/task
> 
> Haiku 5.5 delivers competitive performance for Anthropic's small-model tier.

Archived 2026-10-19 via fxtwitter (unofficial).
Counts: 13,809 views, 184 likes, 12 reposts, 8 replies (at fetch time)
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## Cited in

- 2026-10-15: [ARC Prize verifies Gemini 4 Argon at 97.5% on ARC-AGI-3 with Google's harness (49.8% standard), the second lab above 95%](https://postcutoff.com/e/2026-10-15-arc-agi-3-gemini-4-argon-97-5/)