Claude Opus 4.8 vs Claude Opus 4.8 (Fast)
Opus against its Fast serving: identical family, latency against depth.
What the numbers say
- Claude Opus 4.8 is about 2.0x cheaper on output tokens (275 vs 550 credits per 1M).
- Both take the same 1M-token context window.
- Claude Opus 4.8 (Fast) is the newer release (May 2026 vs May 2026).
Derived from the live registry Zeplik routes and bills against. Credits: 1 credit = $0.10, raw provider rate with a 1.10x margin.
Side by side
Claude Opus 4.8
Anthropic
Claude Opus 4.8 is Anthropic's most capable generally available model in the Opus family. It supports text, image, and file inputs with text output, with reasoning support and a 1M-token...
- Provider
- Anthropic
- Context window
- 1M tokens
- Input price
- 55.0 credits / 1M tokens ($5.00 raw)
- Output price
- 275 credits / 1M tokens ($25.00 raw)
- Vision (image input)
- Yes
- Tool calling
- Yes
- Extended reasoning
- No
Best for
- Hard problems where answer quality matters more than cost: strategy, analysis, difficult writing
- Very long documents and codebases: a 1M-token window fits entire books or repositories in one conversation
- Working with images: screenshots, charts, photos and scanned documents alongside text
- Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows
Claude Opus 4.8 (Fast)
Anthropic
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
- Provider
- Anthropic
- Context window
- 1M tokens
- Input price
- 110 credits / 1M tokens ($10.00 raw)
- Output price
- 550 credits / 1M tokens ($50.00 raw)
- Vision (image input)
- Yes
- Tool calling
- Yes
- Extended reasoning
- No
Best for
- Hard problems where answer quality matters more than cost: strategy, analysis, difficult writing
- Very long documents and codebases: a 1M-token window fits entire books or repositories in one conversation
- Working with images: screenshots, charts, photos and scanned documents alongside text
- Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows
Try both on Zeplik
The honest answer to most model debates is to run your own prompt on both. Zeplik puts Claude Opus 4.8 and Claude Opus 4.8 (Fast) in the same chat, so you can switch mid-conversation and compare answers on the work you actually do.