AI Radar

Claude Opus 4.8

Available · Language, Multimodal, Reasoning

Claude Opus 4.8 is a language model in Anthropic's Claude Opus line, released on 28 May 2026 at the Opus 4.7 price and available on the Claude API and major cloud platforms. It takes text and image input with a 1M token context window, added mid-conversation system messages, and later served as the fallback for requests that Claude Fable 5's safeguards blocked. [1] [2] [3]May 28, 2026 [4] Primary source

Timeline of Claude Opus 4.8 →

Claims and evidence

  • Released Primary source[1] [2]Availability: Released
  • Status Available Primary source[2]Availability [5]Model status table
  • Change · Other Accepts system messages sent mid-conversation, after a user turn, while keeping prompt cache hits.Compared with Claude Opus 4.7 Primary source[3]May 28, 2026
  • Change · Safety Anthropic reports lower rates of misaligned behaviour than Opus 4.7 in its alignment assessment.Compared with Claude Opus 4.7 Primary source[1]
  • Change · Other Anthropic says early testers found it more likely to flag uncertainty about its own work and less likely to make unsupported claims.Compared with Claude Opus 4.7 Primary source[1]
  • Input text, image Primary source[2]Capabilities: Input and output
  • Output text Primary source[2]Capabilities: Input and output
  • Context window 1M tokens Primary source[2]Capabilities: Context window
  • Parameters Not disclosedNot disclosed by Anthropic. No claim madeNo source
  • Access API, consumer app, cloud partner Primary source[1]availability paragraph [2]Availability: Platforms

Lineage

Predecessors

Successors

Based on

Not derived from another model.

Variants and derived

None recorded.

Siblings

None recorded.

All ancestors

All descendants

Variants

No variants recorded in this record.

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