#145 Claude Opus 4.8

Anthropic · Claude Opus 4.8

Released: 28.05.2026 · Source

Text; Coding; Reasoning

Use cases: Coding, Reasoning, Text
Accepts: No verified data
Produces: No verified data

Access

Price USD

Provider	Price USD	Conditions
Anthropic · API	$0.5 / 1M cache-read tokens	Standard · Direct Claude API; base input, 5m/1h cache writes, cache hits and output have separate rates. Not a Claude/Claude Code subscription price.Source · 19.09.2026
Anthropic · API	$6.25 / 1M cache-write tokens	Standard · Direct Claude API; base input, 5m/1h cache writes, cache hits and output have separate rates. Not a Claude/Claude Code subscription price.Source · 19.09.2026
Anthropic · API	$5 / 1M input tokens	Standard · Direct Claude API; base input, 5m/1h cache writes, cache hits and output have separate rates. Not a Claude/Claude Code subscription price.Source · 19.09.2026
Anthropic · API	$25 / 1M output tokens	Standard · Direct Claude API; base input, 5m/1h cache writes, cache hits and output have separate rates. Not a Claude/Claude Code subscription price.Source · 19.09.2026

Evaluator & score

Epoch AI · ECI158.3

Composite index · published model-group index · 20.09.2026 · Higher is better

Snapshot: 2026-09-20 · 90% CI [156.43, 160.71]

Official Epoch AI index; combines own, third-party and developer-reported results. It is not a safety audit or a media-generation score.

Conditions

Epoch Capabilities Index; official model-group estimates

Official ECI model scores, Epoch AI, CC BY 4.0. Composite of own, third-party and developer-reported results. 90% bootstrap interval. Not a per-effort score; export date is the model release date, not measurement date. Methodology: https://epoch.ai/eci#documentation

Epoch AI · Chess Puzzles29 %

Independent run · low · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Chess Puzzles; Epoch AI own run; best score across scorers

Epoch AI own run; Chess Puzzles; version: claude-opus-4-8_low; mode: low; source id: 5u3LkMVq4Dy8CfiwA2EAVr; file: chess_puzzles.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 06.08.2026

Epoch AI · Chess Puzzles34 %

Independent run · max · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Chess Puzzles; Epoch AI own run; best score across scorers

Epoch AI own run; Chess Puzzles; version: claude-opus-4-8_max; mode: max; source id: bwak5Cq3LBthfoboicGZUo; file: chess_puzzles.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 29.05.2026

Epoch AI · Chess Puzzles13 %

Independent run · none · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Chess Puzzles; Epoch AI own run; best score across scorers

Epoch AI own run; Chess Puzzles; version: claude-opus-4-8_none; mode: none; source id: oU38rqq2TvJTxvvPsnEQsH; file: chess_puzzles.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 06.08.2026

Epoch AI · EBR-bench28.571 %

Independent run · max · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

EBR-bench; Epoch AI own run; best score across scorers

Epoch AI own run; EBR-bench; version: claude-opus-4-8_max; mode: max; source id: 3zda4kRmrZfxiafpk8BtMM; file: ebr_bench.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 07.08.2026

Epoch AI · FrontierMath47.241 %

Independent run · max · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

FrontierMath; Epoch AI own run; best score across scorers

Epoch AI own run; source version: claude-opus-4-8_max; file: frontiermath.csv; row: 6dUEQ3YfeMZzSm9ytgiuDi.

Measurement date: 08.06.2026

Epoch AI · FrontierMath-Tier-4-2025-07-01-Private31.25 %

Independent run · max · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

FrontierMath-Tier-4-2025-07-01-Private; Epoch AI own run; best score across scorers

Epoch AI own run; FrontierMath-Tier-4-2025-07-01-Private; version: claude-opus-4-8_max; mode: max; source id: 5x5EAvuecqo3SXnZWpvrJA; file: frontiermath_tier_4.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 08.06.2026

Epoch AI · FrontierMath-Tier-4-v2-Private56.098 %

Independent run · max · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

FrontierMath-Tier-4-v2-Private; Epoch AI own run; best score across scorers

Epoch AI own run; FrontierMath-Tier-4-v2-Private; version: claude-opus-4-8_max; mode: max; source id: JiqgqBTfkGx797uowZgJbk; file: frontiermath_tier_4_v2.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 10.06.2026

Epoch AI · FrontierMath-Tiers-1-3-v2-Private80 %

Independent run · max · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

FrontierMath-Tiers-1-3-v2-Private; Epoch AI own run; best score across scorers

Epoch AI own run; FrontierMath-Tiers-1-3-v2-Private; version: claude-opus-4-8_max; mode: max; source id: GVmgtgKMwEqc54f3jA7auP; file: frontiermath_tiers_1_3_v2.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 10.06.2026

Epoch AI · GPQA Diamond88.384 %

Independent run · low · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

GPQA Diamond; Epoch AI own run; best score across scorers

Epoch AI own run; GPQA diamond; version: claude-opus-4-8_low; mode: low; source id: GThtce6GAmRAS8srQyGQoA; file: gpqa_diamond.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 06.08.2026

Epoch AI · GPQA Diamond91.035 %

Independent run · max · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

GPQA Diamond; Epoch AI own run; best score across scorers

Epoch AI own run; GPQA diamond; version: claude-opus-4-8_max; mode: max; source id: dqgqP2uEPswfECCVj2Kbr9; file: gpqa_diamond.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 07.06.2026

Epoch AI · GPQA Diamond85.354 %

Independent run · none · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

GPQA Diamond; Epoch AI own run; best score across scorers

Epoch AI own run; GPQA diamond; version: claude-opus-4-8_none; mode: none; source id: ckbZdkrXPwbFdjn6bmUQsi; file: gpqa_diamond.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 06.08.2026

Epoch AI · Mock AIME 2024/202597.778 %

Independent run · low · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Mock AIME 2024/2025; Epoch AI own run; best score across scorers

Epoch AI own run; OTIS Mock AIME 2024-2025; version: claude-opus-4-8_low; mode: low; source id: MEhV5sh6nbM8cKJGQ6HzcS; file: otis_mock_aime_2024_2025.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 06.08.2026

Epoch AI · Mock AIME 2024/202598.333 %

Independent run · max · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Mock AIME 2024/2025; Epoch AI own run; best score across scorers

Epoch AI own run; OTIS Mock AIME 2024-2025; version: claude-opus-4-8_max; mode: max; source id: 37pJqPpXTE6ia9ikmmGPJ4; file: otis_mock_aime_2024_2025.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 07.06.2026

Epoch AI · Mock AIME 2024/202584.444 %

Independent run · none · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Mock AIME 2024/2025; Epoch AI own run; best score across scorers

Epoch AI own run; OTIS Mock AIME 2024-2025; version: claude-opus-4-8_none; mode: none; source id: adGE8rXdNuUFs96ioppbc5; file: otis_mock_aime_2024_2025.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 06.08.2026

Epoch AI · Mystery Game Puzzles36 %

Independent run · max · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Mystery Game Puzzles; Epoch AI own run; best score across scorers

Epoch AI own run; Mystery Game Puzzles; version: claude-opus-4-8_max; mode: max; source id: Q3WpHdurYNvawj6ycXyj6e; file: mystery_game_puzzles.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 25.07.2026

Epoch AI · Mystery Game Puzzles31 %

Independent run · xhigh · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Mystery Game Puzzles; Epoch AI own run; best score across scorers

Epoch AI own run; Mystery Game Puzzles; version: claude-opus-4-8_xhigh; mode: xhigh; source id: 3ZnPtGRJkvqHk8wvWWRgCe; file: mystery_game_puzzles.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 26.07.2026

Epoch AI · SimpleQA Verified53 %

Independent run · max · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

SimpleQA Verified; Epoch AI own run; best score across scorers

Epoch AI own run; SimpleQA Verified; version: claude-opus-4-8_max; mode: max; source id: ViC6pxQZUVS3E9M9iEubF7; file: simpleqa_verified.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 27.08.2026

SourceVerified 18.09.2026