Model comparison
GPT-OSS 120B vs o3-mini
Head-to-head evidence from 5 shared benchmark results across 3 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-OSS 120B #122 (Supported); o3-mini #141 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-OSS 120B and o3-mini share 5 comparable benchmark results. 0 of 8 categories are comparable. 20 results are unique to GPT-OSS 120B; 5 to o3-mini.
Updated July 24, 2026- Shared results
- 5
- GPT-OSS 120B only
- 20
- o3-mini only
- 5
- Comparable categories
- 0 / 8
Benchmark data for GPT-OSS 120B and o3-mini is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 5 shared benchmark results across 3 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-mini is priced at $1.10 input / $4.40 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for GPT-OSS 120B. o3-mini 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-mini |
|---|---|---|---|
| Coding | GPT-OSS 120BNot measured | MarginNo overlap | o3-mini49.3 |
| Knowledge | GPT-OSS 120BNot measured | MarginNo overlap | o3-mini77.2 |
| Inst. Following | GPT-OSS 120BNot measured | MarginNo overlap | o3-mini93.9 |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-OSS 120B | o3-mini | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-OSS 120B$0 input / $0 output | o3-mini$1.1 input / $4.4 output | GPT-OSS 120B has the lower combined listed price. |
| Generation speedtokens per second | GPT-OSS 120B262 tok/s | o3-mini160 tok/s | GPT-OSS 120B has the higher measured throughput. |
| First-answer latencyseconds to first token | GPT-OSS 120B0.79 s | o3-mini7.12 s | GPT-OSS 120B reaches the first token sooner. |
| Context windowmaximum listed tokens | GPT-OSS 120B128K | o3-mini200K | o3-mini lists the larger context window. |
Benchmark Deep Dive
Agentic7 benchmarks
| Benchmark | GPT-OSS 120B | o3-mini | Result |
|---|---|---|---|
| AA Agentic IndexSource | 13.2% | — | Not comparable |
| APEX-Agents-AASource | 3.1% | — | Not comparable |
| τ²-bench resultsSource | 65.8% | 28.7% | GPT-OSS 120B leads |
| GDPval-AASource | 15.1% | — | Not comparable |
| GDPval-AASource | 802 | — | Not comparable |
| Gert LabsSource | 29.61% | — | Not comparable |
| AA ITBenchSource | 5.6% | — | Not comparable |
Coding5 benchmarks
Reasoning2 benchmarks
Knowledge10 benchmarks
| Benchmark | GPT-OSS 120B | o3-mini | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 23.8% | 19.0% | GPT-OSS 120B leads |
| AA-GPQA DiamondSource | 78.2% | 74.8% | GPT-OSS 120B leads |
| AA-HLESource | 18.5% | 8.7% | GPT-OSS 120B leads |
| AA-Omniscience IndexSource | -50.0% | — | Not comparable |
| AA-Omniscience AccuracySource | 21.5% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 91.2% | — | Not comparable |
| AA Openness IndexSource | 38.9% | — | Not comparable |
| AA MMLU-ProSource | 80.8% | — | Not comparable |
| MMLUSource | — | 86.9% | Not comparable |
| GPQASource | — | 77.2% | Not comparable |
Math2 benchmarks
Multilingual1 benchmarks
| Benchmark | GPT-OSS 120B | o3-mini | Result |
|---|---|---|---|
| AA Global-MMLU-LiteSource | 82.8% | — | Not comparable |
Multimodal1 benchmarks
| Benchmark | GPT-OSS 120B | o3-mini | Result |
|---|---|---|---|
| Design Arena WebsiteSource | 998 | — | Not comparable |
Frequently Asked Questions (3)
Can I compare GPT-OSS 120B and o3-mini 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-mini today?
GPT-OSS 120B: $0.00 input / $0.00 output per 1M tokens o3-mini: $1.10 input / $4.40 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.