Anthropic · Claude Opus
Claude Opus 4.8
A high-capability Claude model for complex agentic coding and enterprise work, now superseded by Claude Opus 5 but still available on every platform that carried it.
Treat this as a migration entry rather than a recommendation. If you are choosing a model today the comparison is Opus 5 against Sonnet 5, and the migration carries two behaviour changes worth testing: thinking on by default, and disabling thinking rejected above high effort.
Use it for
- Existing integrations not yet migrated to Opus 5
- Long-horizon agentic coding
- Enterprise work with heavy context
It is poor value when a Sonnet-class model already passes the task, and it is no longer the model to start a new build on: Anthropic lists it as legacy and points new work at Opus 5.
Effort without the jargon
The workload mixes simple steps with complex ones and should reason only when the turn calls for it. Note that thinking is off unless requested here, which is the reverse of Opus 5.
Advanced recordCost, limits, privacy and operations
Opus buys more capability at a higher token price; the practical question is whether it reduces enough failed attempts or review time to beat Sonnet on your task.
- API cost
- Officially disclosedClaude API list price: US$5 per million input tokens and US$25 per million output tokens; caching, batch and cloud-platform rates can differ.
- Context window
- Officially disclosed1,000,000 tokens
- Maximum output
- Officially disclosed128,000 tokens (synchronous Messages API)
- Knowledge cutoff
- Officially disclosedReliable knowledge: January 2026; training data: January 2026
- Recorded inputs
- Text · Images
- Recorded output
- Text
Data handling is a product decision
Depends on surfaceAnthropic says commercial API inputs and outputs are deleted from its backend within 30 days by default, with exceptions for stored services, agreed controls, safety enforcement and law. Consumer Claude and cloud platforms have separate terms.
Operational constraints
- Effort defaults to high on the API, Claude Code and claude.ai unless set explicitly.
- The dateless API ID is a pinned snapshot, so migration remains a deliberate change.
- Cloud-platform endpoint, routing and pricing conditions can differ from the first-party API.
Unknown means the cited official record does not disclose a safe value. It is not an estimate. Prices are provider list prices in USD where stated and can change before this record's review date.
Keep the evidence separate
Anthropic now lists Opus 4.8 among its legacy models and names Claude Opus 5 as the model for complex agentic coding and enterprise work. Opus 4.8 remains available on the Claude API, AWS, Google Cloud and Microsoft Foundry.
No sufficiently useful independent note has been added yet. That absence is not filled with our guess.
No Human Bit result is claimed; use this as evaluation guidance only.
Not scheduled
No Human Bit result is claimed for this model yet.