Claude Mythos 5: Price, Context, Benchmarks, and Release Details
51.7
SI Score (method si-v3-retained-evidence-2)
5% confidence 5 percent, Low confidence — 1 of 8 expected sources in
Coverage 4% of expected source weight · 100% confidence at 80% coverage
Pillar breakdown
Coding (weight 40 percent) 87.9
Math (weight 15 percent) —
Preference (weight 15 percent) —
Reasoning (weight 30 percent) 94.1
Pillar weights: reasoning 30% · math 15% · coding 40% · preference 15%. Benchmark results use fixed 0–100 scales before averaging; incomplete evidence is shrunk toward 50.
Facts
- Input price / 1M
- $10.00Anthropic API pricingOfficial Claude API base tokens; lowest short-context global Standard rate; cache, batch, fast and regional premiums excluded
Retrieved Oct 9, 2026 · factual citation
Open source ↗ - Output price / 1M
- $50.00Anthropic API pricingOfficial Claude API base tokens; lowest short-context global Standard rate; cache, batch, fast and regional premiums excluded
Retrieved Oct 9, 2026 · factual citation
Open source ↗ - Context window
- 1Mmodels.devPublished source fact
Retrieved Oct 9, 2026 · MIT
Open source ↗ - Max output
- 128Kmodels.devPublished source fact
Retrieved Oct 9, 2026 · MIT
Open source ↗ - Released
- Jun 9, 2026models.devPublished source fact
Retrieved Oct 9, 2026 · MIT
Open source ↗ - Open weights
- Nomodels.devPublished source fact
Retrieved Oct 9, 2026 · MIT
Open source ↗ - License
- not yet reported
- Input modalities
- text, image, pdfmodels.devPublished source fact
Retrieved Oct 9, 2026 · MIT
Open source ↗
Benchmark results
4 results| Benchmark | Raw result | Normalized (0–100) | Pillar |
|---|---|---|---|
| gpqa diamond | 94.1%Anthropic Mythos 5 system-card claimsLab claim, not an independent evaluation. 198-question GPQA Diamond, average over 5 trials; June 9 release card section 8.8; immutable edition [variant] Mythos 5 system cardPublished Jun 9, 2026
Retrieved Oct 9, 2026 · factual citation Open source ↗ | 94.1 | reasoning |
| swe bench pro system card 2026 06 | 80.3%Anthropic Mythos 5 system-card claimsLab claim, not an independent evaluation. System-card variant; public/private split unspecified, kept separate from the public steward board; June 9 release card, section 8; immutable edition [variant] Mythos 5 system cardPublished Jun 9, 2026
Retrieved Oct 9, 2026 · factual citation Open source ↗ | 80.3 | coding |
| swe bench verified | 95.5%Anthropic Mythos 5 system-card claimsLab claim, not an independent evaluation. Anthropic internal harness, thinking enabled; average over 5 trials; June 9 release card, section 8; immutable edition [variant] Mythos 5 system cardPublished Jun 9, 2026
Retrieved Oct 9, 2026 · factual citation Open source ↗ | 95.5 | coding |
| terminal bench v2 1 | 88%Anthropic Mythos 5 system-card claimsLab claim, not an independent evaluation. mini-SWE-agent, GKE, 1x timeout and 3x memory; high effort; 445 trials; June 9 release card, section 8; immutable edition [variant] Mythos 5 system cardPublished Jun 9, 2026
Retrieved Oct 9, 2026 · factual citation Open source ↗ | 88.0 | coding |
Normalization uses fixed absolute 0–100 scales for each unit, independently of other models that have a result on each benchmark. Coverage and evidence breadth still affect the composite; compare the evaluation conditions before reading a small score gap as decisive. “lab-reported” marks the provider's own published figure.
Sources: in and pending
in Reported (1)
- Anthropic Mythos 5 system-card claims · arrived Oct 8, 2026
pending Awaiting (7)
- ARC Prize · carries 12% of expected weight
- Epoch AI Benchmarking · carries 24% of expected weight
- Humanity’s Last Exam · carries 12% of expected weight
- Official model cards via models.dev · carries 4% of expected weight
- LiveBench · carries 12% of expected weight
- LMArena / Arena · carries 24% of expected weight
- Terminal-Bench · carries 6% of expected weight
The confidence % rises as pending sources publish. Some sources never cover some models — that is why 100% confidence arrives at 80% of expected weight, not at full coverage.