Model comparison
GPT-OSS 120B vs o3
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-OSS 120B #116 (Supported); o3 #131 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-OSS 120B and o3 share 12 comparable benchmark results. 0 of 8 categories are comparable. 14 results are unique to GPT-OSS 120B; 4 to o3.
Updated July 22, 2026- Shared results
- 12
- GPT-OSS 120B only
- 14
- o3 only
- 4
- Comparable categories
- 0 / 8
Benchmark data for GPT-OSS 120B and o3 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.
o3 is priced at $2.00 input / $8.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for GPT-OSS 120B. o3 has the larger context window at 200K, compared with 128K 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-OSS 120B | Δ | o3 |
|---|---|---|---|
| Math | GPT-OSS 120BNot measured | MarginNo overlap | o314.5 |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-OSS 120B | o3 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-OSS 120B$0 input / $0 output | o3$2 input / $8 output | GPT-OSS 120B has the lower combined listed price. |
| Generation speedtokens per second | GPT-OSS 120B262 tok/s | o3118 tok/s | GPT-OSS 120B has the higher measured throughput. |
| First-answer latencyseconds to first token | GPT-OSS 120B0.79 s | o35.38 s | GPT-OSS 120B reaches the first token sooner. |
| Context windowmaximum listed tokens | GPT-OSS 120B128K | o3200K | o3 lists the larger context window. |
Benchmark Deep Dive
Agentic8 benchmarks
| Benchmark | GPT-OSS 120B | o3 | Result |
|---|---|---|---|
| AA Agentic IndexSource | 13.2% | — | Not comparable |
| APEX-Agents-AASource | 3.1% | — | Not comparable |
| τ²-bench resultsSource | 65.8% | 80.7% | o3 leads |
| 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 ITBenchSource | 5.6% | — | Not comparable |
Coding4 benchmarks
Reasoning2 benchmarks
Knowledge8 benchmarks
| Benchmark | GPT-OSS 120B | o3 | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 23.8% | 30.4% | o3 leads |
| AA-GPQA DiamondSource | 78.2% | 82.7% | o3 leads |
| AA-HLESource | 18.5% | 20.0% | o3 leads |
| AA-Omniscience IndexSource | -50.0% | -15.3% | o3 leads |
| AA-Omniscience AccuracySource | 21.5% | 38.4% | o3 leads |
| AA-Omniscience Hallucination RateSource | 91.2% | 87.1% | o3 leads |
| AA Openness IndexSource | 38.9% | — | Not comparable |
| AA MMLU-ProSource | 80.8% | — | Not comparable |
Math4 benchmarks
Multilingual1 benchmarks
| Benchmark | GPT-OSS 120B | o3 | Result |
|---|---|---|---|
| AA Global-MMLU-LiteSource | 82.8% | — | Not comparable |
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | GPT-OSS 120B | o3 | Result |
|---|---|---|---|
| AA-IFBenchSource | 69.0% | 71.4% | o3 leads |
Frequently Asked Questions (3)
Can I compare GPT-OSS 120B and o3 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-OSS 120B and o3 today?
GPT-OSS 120B: $0.00 input / $0.00 output per 1M tokens o3: $2.00 input / $8.00 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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