Fast-mode variant of [Opus 4.8](/anthropic/claude-opus-4.8) - identical capabilities with higher output speed at 2x pricing relative to regular Opus 4.8. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-mode
Details
| Field | Value |
|---|---|
| id | anthropic/claude-opus-4.8-fast |
| family | claude-opus |
| modality | text+image+pdf->text |
| context_length | 1000000 |
| max_output_tokens | 128000 |
| knowledge_cutoff | 2026-01 |
| release_date | 2026-05-28 |
| is_open_weights | no |
| supports_tool_call | yes |
| supports_reasoning | yes |
| supports_structured_output | yes |
| supports_attachment | yes |
| input_modalities | text, image, pdf |
| output_modalities | text |