Claude Opus 5 Fast
claude-opus-5-fastopus-5-fast- ⚡ Speed-optimized Opus 5, running about 2.5x default speed
- 📏 Full 1M-token context window, same as standard Opus 5
- 🧠 Reasoning, vision, coding, function-calling and web search onboard
- 🏢 Built for agentic coding and professional knowledge work
- 🎯 Effort setting trades intelligence for faster, cheaper output
- 🔧 Same weights as Opus 5, priority serving path, higher token cost
- 🆕 Succeeds Claude Opus 4.8 Fast in the Opus fast family
- 📅 Released alongside Claude Opus 5 in July 2026
Anthropic PBC is an American artificial intelligence company headquartered in San Francisco. Structured as a public benefit corporation, the lab develops large language models under the Claude name, with a research emphasis on building reliable, steerable, and safety-focused AI…
Explore 12 more models by Anthropic →Claude Opus 5 Fast is the latency-optimized configuration of Anthropic's [[sibling:claude-opus-5|Claude Opus 5]], the flagship of the Opus tier released in July 2026. Rather than a distinct model, fast mode routes requests through a higher-priority serving path so the same Opus 5 weights respond at roughly 2.5 times the default speed, at a higher per-token cost. It keeps the full 1M-token context window and the model's capabilities across reasoning, vision, agentic coding, function calling and web search.
Within its own family, it directly follows [[sibling:claude-opus-4-8-fast|Claude Opus 4.8 Fast]], inheriting the underlying generational jump from [[sibling:claude-opus-4-8|Claude Opus 4.8]] to Opus 5. Anthropic says Opus 5 delivers improved performance at the same price as Opus 4.8, and reports it scores 10.2 percentage points higher than Opus 4.8 on the company's internal chemistry benchmark, calling it their most capable generally available model for scientific research.
Opus 5 sits below the Mythos-class [[sibling:claude-fable-5|Claude Fable 5]] in Anthropic's lineup, with [[sibling:claude-sonnet-5|Claude Sonnet 5]] serving as the more balanced mid-tier option. The fast variant is aimed at interactive work like rapid iteration and live debugging, where lower latency matters more than conserving cost.
This About section is AI-generated from public sources via VeniceStats + Venice inference, with no human editing. It may contain inaccuracies.
| Seller | Reputation↓ | Routing | Input $/M | Cached $/M | Output $/M | Categories | API |
|---|---|---|---|---|---|---|---|
| Fire Ant 🔥🐜 0xbe05…bc5d | 37 | gated | $10.2447 | $1.0245 | $51.2236 | chat | — |
| antseed-opal-badger-2580 0xc85d…2580 | 2 | gated | $6.00 | $6.00 | $30.00 | chat | openai-chat-completions |
"Best price" and the seller table are live AntSeed catalog data (advertised $/1M tokens — or $ per generated image for unit-billed image models — not settled amounts). Reputation = on-chain trust (0-100). "Routing" = the SDK's default buyer routing (what the VPR desktop app ships with): a trust ≥ 60 gate on the effective reputation, then cheapest-first among routable sellers; live failover state (per-peer cooldowns) is buyer-side runtime and not included. Model knowledge (TLDR, provider, About) via the VeniceStats enrichment layer. Advertised catalog, not the model used in any specific purchase. "Usage on AntSeed" counts only settlements whose buyers share the per-model split on-chain (metadata v2/v3, opt-in), so every usage figure is a lower bound.