Model comparison
GPT-4o vs GPT-OSS 120B
Head-to-head evidence from 12 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-4o #165 (Supported); GPT-OSS 120B #116 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-4o and GPT-OSS 120B share 12 comparable benchmark results. 0 of 8 categories are comparable. 1 result is unique to GPT-4o; 15 to GPT-OSS 120B.
Updated July 20, 2026- Shared results
- 12
- GPT-4o only
- 1
- GPT-OSS 120B only
- 15
- Comparable categories
- 0 / 8
Benchmark data for GPT-4o and GPT-OSS 120B is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 12 shared benchmark results across 6 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
GPT-4o is priced at $2.50 input / $10.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for GPT-OSS 120B.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | GPT-4o | Δ | GPT-OSS 120B |
|---|---|---|---|
| Math | GPT-4o0.3 | MarginNo overlap | GPT-OSS 120BNot measured |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-4o | GPT-OSS 120B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-4o$2.5 input / $10 output | GPT-OSS 120B$0 input / $0 output | GPT-OSS 120B has the lower combined listed price. |
| Generation speedtokens per second | GPT-4o131 tok/s | GPT-OSS 120B262 tok/s | GPT-OSS 120B has the higher measured throughput. |
| First-answer latencyseconds to first token | GPT-4o0.81 s | GPT-OSS 120B0.79 s | GPT-OSS 120B reaches the first token sooner. |
| Context windowmaximum listed tokens | GPT-4o128K | GPT-OSS 120B128K | Listed context windows are equal. |
Benchmark Deep Dive
Agentic9 benchmarks
| Benchmark | GPT-4o | GPT-OSS 120B | Result |
|---|---|---|---|
| τ²-bench resultsSource | 25.1% | 65.8% | GPT-OSS 120B leads |
| AA Agentic IndexSource | — | 13.2% | Not comparable |
| APEX-Agents-AASource | — | 3.1% | Not comparable |
| GDPval-AASource | — | 15.0% | Not comparable |
| GDPval-AASource | — | 799 | Not comparable |
| Gert LabsSource | — | 29.61% | Not comparable |
| AA EnterpriseOps-GymSource | — | 25.5% | Not comparable |
| AA Harvey LABSource | — | 0.0% | Not comparable |
| AA ITBenchSource | — | 5.6% | Not comparable |
Coding4 benchmarks
Reasoning2 benchmarks
Knowledge8 benchmarks
| Benchmark | GPT-4o | GPT-OSS 120B | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 11.2% | 23.8% | GPT-OSS 120B leads |
| AA-GPQA DiamondSource | 54.3% | 78.2% | GPT-OSS 120B leads |
| AA-HLESource | 3.3% | 18.5% | GPT-OSS 120B leads |
| AA-Omniscience IndexSource | -10.7% | -50.0% | GPT-4o leads |
| AA-Omniscience AccuracySource | 19.7% | 21.5% | GPT-OSS 120B leads |
| AA-Omniscience Hallucination RateSource | 37.9% | 91.2% | GPT-4o leads |
| AA Openness IndexSource | — | 38.9% | Not comparable |
| AA MMLU-ProSource | — | 80.8% | Not comparable |
Math2 benchmarks
Multilingual1 benchmarks
| Benchmark | GPT-4o | GPT-OSS 120B | Result |
|---|---|---|---|
| AA Global-MMLU-LiteSource | — | 82.8% | Not comparable |
Multimodal1 benchmarks
| Benchmark | GPT-4o | GPT-OSS 120B | Result |
|---|---|---|---|
| Design Arena WebsiteSource | 864 | 1000 | GPT-OSS 120B leads |
Inst. Following1 benchmarks
| Benchmark | GPT-4o | GPT-OSS 120B | Result |
|---|---|---|---|
| AA-IFBenchSource | 34.3% | 69.0% | GPT-OSS 120B leads |
Frequently Asked Questions (3)
Can I compare GPT-4o and GPT-OSS 120B on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for GPT-4o and GPT-OSS 120B today?
GPT-4o: $2.50 input / $10.00 output per 1M tokens GPT-OSS 120B: $0.00 input / $0.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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