Model comparison
Composer 2 Fast vs GPT-5.4 mini
Head-to-head evidence from 0 shared benchmark results across 0 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Composer 2 Fast unranked (Not scored); GPT-5.4 mini #81 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Composer 2 Fast and GPT-5.4 mini share 0 comparable benchmark results. 0 of 8 categories are comparable. 1 result is unique to Composer 2 Fast; 30 to GPT-5.4 mini.
Updated July 28, 2026- Shared results
- 0
- Composer 2 Fast only
- 1
- GPT-5.4 mini only
- 30
- Comparable categories
- 0 / 8
Benchmark data for Composer 2 Fast and GPT-5.4 mini is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 0 shared benchmark results across 0 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-5.4 mini has the larger context window at 400K, compared with 200K for Composer 2 Fast.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Composer 2 Fast | GPT-5.4 mini | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Composer 2 FastNot available | GPT-5.4 mini$0.75 input / $4.5 output | A complete price comparison is not available. |
| Generation speedtokens per second | Composer 2 FastNot available | GPT-5.4 mini201 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Composer 2 FastNot available | GPT-5.4 mini3.85 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Composer 2 Fast200K | GPT-5.4 mini400K | GPT-5.4 mini lists the larger context window. |
Benchmark Deep Dive
Agentic9 benchmarks
| Benchmark | Composer 2 Fast | GPT-5.4 mini | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | — | 60% | Not comparable |
| OSWorld-VerifiedSource | — | 72.1% | Not comparable |
| MCP AtlasSource | — | 57.7% | Not comparable |
| ToolathlonSource | — | 42.9% | Not comparable |
| τ²-bench resultsSource | — | 93.4% | Not comparable |
| AA Agentic IndexSource | — | 30.2% | Not comparable |
| APEX-Agents-AASource | — | 28.2% | Not comparable |
| GDPval-AASource | — | 33.5% | Not comparable |
| GDPval-AASource | — | 1169 | Not comparable |
Coding5 benchmarks
Reasoning2 benchmarks
Knowledge9 benchmarks
| Benchmark | Composer 2 Fast | GPT-5.4 mini | Result |
|---|---|---|---|
| GPQASource | — | 88% | Not comparable |
| HLESource | — | 41.5% | Not comparable |
| HLE w/o toolsSource | — | 28.2% | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 40.0% | Not comparable |
| AA-GPQA DiamondSource | — | 87.5% | Not comparable |
| AA-HLESource | — | 26.6% | Not comparable |
| AA-Omniscience IndexSource | — | -18.7% | Not comparable |
| AA-Omniscience AccuracySource | — | 37.5% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 89.8% | Not comparable |
Math2 benchmarks
Multimodal3 benchmarks
Inst. Following1 benchmarks
| Benchmark | Composer 2 Fast | GPT-5.4 mini | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 73.3% | Not comparable |
Frequently Asked Questions (3)
Can I compare Composer 2 Fast and GPT-5.4 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 Composer 2 Fast and GPT-5.4 mini today?
GPT-5.4 mini: $0.75 input / $4.50 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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