What is Claude Opus 4.8?
Claude Opus 4.8 is Anthropic's most capable model, released on May 28, 2026. It builds on Claude Opus 4.7 with improvements across coding, agentic tasks, reasoning, and practical knowledge work. Pricing is unchanged from Opus 4.7 at $5 per million input tokens and $25 per million output tokens.
Key Improvements in Claude Opus 4.8
The most prominent improvement is honesty — Opus 4.8 is approximately four times less likely than its predecessor to let flaws in code pass unremarked. It flags uncertainties proactively rather than confidently claiming progress when evidence is thin.
Early testers from Cursor, Devin, Hebbia, and CoCounsel Legal report that Opus 4.8 has better judgment, catches its own mistakes, and pushes back when a plan isn't sound. On CursorBench it exceeds all prior Opus models at every effort level. On the Legal Agent Benchmark it achieves the highest score ever recorded, breaking 10% on the all-pass standard for the first time.
New Features Launching with Opus 4.8
Dynamic Workflows (research preview in Claude Code) allows Claude to plan work and run hundreds of parallel subagents in a single session. It can carry out codebase-scale migrations across hundreds of thousands of lines of code from kickoff to merge. Available in Claude Code for Enterprise, Team, and Max plans.
Effort Control in claude.ai lets users choose how much effort Claude puts into a response — higher effort for better quality, lower effort for faster responses that use rate limits more slowly.
Fast Mode for Opus 4.8 runs at 2.5x speed and is now three times cheaper than for previous models ($10/$50 per million tokens).
Claude Opus 4.8 Pricing
Regular usage: $5 per million input tokens, $25 per million output tokens — unchanged from Opus 4.7. Fast mode: $10 per million input tokens, $50 per million output tokens. API model string: claude-opus-4-8.
What's Next from Anthropic?
Anthropic has announced plans for a new class of model with even higher intelligence than Opus — Mythos-class models, currently in research preview via Project Glasswing. General availability is expected in the coming weeks.
Frequently Asked Questions
What is the Claude Opus 4.8 API model string?
The API identifier is claude-opus-4-8, available via the Anthropic API, AWS Bedrock, and Google Cloud Vertex AI.
How much does Claude Opus 4.8 cost?
$5 per million input tokens and $25 per million output tokens for regular usage. Fast mode is $10/$50 per million tokens.
What is improved in Opus 4.8 vs Opus 4.7?
Opus 4.8 is 4x less likely to miss code flaws, scores higher on legal, coding, and agentic benchmarks, and is more honest about uncertainty. It also supports Dynamic Workflows for large-scale parallel agentic tasks in Claude Code.