Claude Opus 4.8
May 2026 · Proprietary · Superseded · supported evidence
Last-gen Opus at current Opus 5 prices. Keep it only if a harness is pinned; otherwise move to Opus 5.
Intelligence
57.3
AA Index
API price
$5 / $25
Input / output per 1M
Context
1M
58 tok/s
Capability
Intelligence Index57.3
Coding index73
Agentic index54
Arena Elo (offset)161
Use it when
- ▸Pinned eval harnesses
Skip if
- –You can switch to Opus 5 at the same list price
Benchmarks
GPQA Diamond Graduate-level science questions designed so Google search is not enough. Still one of the cleanest knowledge/reasoning splits. | 93.6% |
|---|---|
Humanity’s Last Exam Expert-written questions across fields. Harder than MMLU; the current differentiator for “does this model actually know things.” | — |
MMLU-Pro Harder, less-saturated successor to MMLU. Classic MMLU is above 90% for every flagship and no longer ranks the field. | — |
SWE-bench Verified 500 human-validated GitHub issues. Score swings 5–15 points by harness — treat vendor numbers as an upper bound. | 88.6% |
SWE-bench Pro Harder, contamination-resistant coding eval. Currently the best public split between “can code” and “can maintain a repo.” | 69.2% |
Terminal-Bench 2.1 End-to-end tasks in a real terminal. Better proxy for coding agents than HumanEval, which is fully saturated. | 74.6% |
ARC-AGI-2 Abstract visual puzzles. Rewards generalization over memorization. GPT-5.6 Sol currently leads the published set. | — |
AIME 2025 American Invitational Mathematics Examination. Contest math; reasoning-mode models dominate. | — |
MMMU College-level multimodal understanding across diagrams, charts, and exam figures. | — |
Modalities
text · vision · tools
Reasoning mode
hybrid
Hybrid and reasoning models spend tokens thinking. That raises GPQA and agents, and also raises latency and bill.