Compare / head-to-head
GPT-4ovsgpt-oss-20b
gpt-oss-20b leads 3 of 3 shared benchmarks. gpt-oss-20b has the larger context window (131K tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
0 – 3
gpt-oss-20b leads
Cheaper per token
—
list price, input + output
Larger context
gpt-oss-20b
131K tokens
Provider uptime (30d)
94.7712%
OpenAI
GPT-4o
OpenAI · released 2024-05-13
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
3 shared · 5 only GPT-4o · 2 only gpt-oss-20b| Benchmark | GPT-4o | gpt-oss-20b | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 3 | ||||
| GPQA Diamond | 46% ↗ | 71.5% ↗ | -25.5 pt | gpt-oss-20b |
| AIME 2025 | 11.7% ↗matharena | 89.2% ↗matharena ⚠ | -77.5 pt | gpt-oss-20b |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 6.4% ↗epoch | 65.3% ↗epoch | -58.9 pt | gpt-oss-20b |
| Only GPT-4o reports · 5 | ||||
| MMLU | 85.7% ↗ | not reported | — | — |
| AIME 2024 | 13.1% ↗ | not reported | — | — |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 0.4% ↗epoch | not reported | — | — |
| SimpleQA Verified | 26% ↗epoch | not reported | — | — |
| SWE-bench Verified (Epoch AI run) | 31% ↗epoch | not reported | — | — |
| Only gpt-oss-20b reports · 2 | ||||
| SWE-bench Verified | not reported | 60.7% ↗ | — | — |
| 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 GPT-4o 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 | GPT-4o | gpt-oss-20b | Edge |
|---|---|---|---|
| Context window | 128K tokens | 131K tokens | gpt-oss-20b |
| Max output | 16K tokens | 131K tokens | gpt-oss-20b |
| Input price / 1M | $2.5 ↗ | — | — |
| Output price / 1M | $10 ↗ | — | — |
| Cached input / 1M | $1.25 ↗ | — | — |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $12.5 | — | — |
| Modalities | text · vision | text | GPT-4o |
| Released | 2024-05-13 | 2025-08-05 | — |
| Cited benchmark scores | 9 | 6 | — |
Reliability
OpenAI status
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Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run GPT-4o and gpt-oss-20b on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.