Compare / head-to-head
Claude Opus 5vsgpt-oss-20b
Claude Opus 5 leads 2 of 2 shared benchmarks. Claude Opus 5 has the larger context window (1M tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
2 – 0
Claude Opus 5 leads
Cheaper per token
—
list price, input + output
Larger context
Claude Opus 5
1M tokens
Provider uptime (30d)
100% · 95.3757%
Anthropic · OpenAI
Claude Opus 5
Anthropic · released 2026-07-24
textvision
gpt-oss-20b
OpenAI · released 2025-08-05
text
- Context
- 131K
- Max out
- 131K
- Input /1M
- —
- Output /1M
- —
- Cached /1M
- —
- Scores
- 6 · 5 core
Quality
Benchmark matrix
2 shared · 7 only Claude Opus 5 · 3 only gpt-oss-20b| Benchmark | Claude Opus 5 | gpt-oss-20b | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 2 | ||||
| GPQA Diamond | 93.9% ↗epoch | 71.5% ↗ | +22.4 pt | Claude Opus 5 |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 98.9% ↗epoch | 65.3% ↗epoch | +33.6 pt | Claude Opus 5 |
| Only Claude Opus 5 reports · 7 | ||||
| Humanity's Last Exam (no tools) | 56.6% ↗ | not reported | — | — |
| CursorBench 3.2.0 | 70% ↗ | not reported | — | — |
| FrontierMath Tier 4 v2 (Epoch AI run) | 73.2% ↗epoch | not reported | — | — |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 85.6% ↗epoch | not reported | — | — |
| GDPval-AA v2 | 1824 ↗ | not reported | — | — |
| SimpleQA Verified | 59.9% ↗epoch | not reported | — | — |
| Terminal-Bench Science 0.1 | 29% ↗ | not reported | — | — |
| Only gpt-oss-20b reports · 3 | ||||
| SWE-bench Verified | not reported | 60.7% ↗ | — | — |
| AIME 2025 | not reported | 89.2% ↗matharena ⚠ | — | — |
| LMArena Elo | not reported | 1287.3 ↗ | — | — |
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is Claude Opus 5 minus gpt-oss-20b in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing
Side by side
Official pricing pages and model cards| Spec | Claude Opus 5 | gpt-oss-20b | Edge |
|---|---|---|---|
| Context window | 1M tokens | 131K tokens | Claude Opus 5 |
| Max output | 128K tokens | 131K tokens | gpt-oss-20b |
| Input price / 1M | $5 ↗ | — | — |
| Output price / 1M | $25 ↗ | — | — |
| Cached input / 1M | $0.5 ↗ | — | — |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $30 | — | — |
| Modalities | text · vision | text | Claude Opus 5 |
| Released | 2026-07-24 | 2025-08-05 | — |
| Cited benchmark scores | 9 | 6 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
Claude Opus 5 vs …
Models sharing the most benchmarksMore matchups
gpt-oss-20b vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run Claude Opus 5 and gpt-oss-20b on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.