DeepSeek V4 Flash vs GPT-5.4
DeepSeek V4 Flash 
GPT-5.4 Verdict
- GPT-5.4 (xhigh) leads on quality: 65.4 vs 62.1.
- DeepSeek V4 Flash (max) is stronger in agents & tools, composite, instruction following, reasoning.
- GPT-5.4 (xhigh) is stronger in coding, knowledge, long context, maths, multimodal.
- DeepSeek V4 Flash (max) is 21× cheaper ($0.262 vs $5.63 per 1M blended).
- DeepSeek V4 Flash (max) streams 1.7× faster (212 vs 121 tokens per second).
| Metric | DeepSeek V4 Flash (max) | GPT-5.4 (xhigh) |
|---|---|---|
| BenchLeader Index | 62.1 | 65.4 |
| Agents & tools score | 67.0 | 63.4 |
| Coding score | 49.1 | 66.6 |
| Composite score | 72.8 | 69.4 |
| Instruction following score | 76.7 | 72.1 |
| Knowledge score | 57.4 | 60.6 |
| Long context score | 66.3 | 67.5 |
| Maths score | 57.3 | 66.4 |
| Reasoning score | 73.9 | 72.4 |
| Multimodal score | – | 62.9 |
| Blended price $/M | $0.262 | $5.63 |
| Output speed | 212 tok/s | 121 tok/s |
| Time to first answer | 10.6 s | 141.3 s |
| Context window | 1M | 1.1M |
| GPQA Diamond | – | 93.3% |
| FrontierMath Tiers 1–3 | – | 78.6% |
| FrontierMath Tier 4 | – | 49.0% |
| OTIS Mock AIME | – | 95.3% |
| SimpleQA Verified | – | 45.1% |
| Humanity's Last Exam | – | 36.2% |
| SciCode | 44.9% | 56.6% |
| WeirdML | 45.6% | 77.7% |
| APEX-Agents | – | 36.0% |
| ProofBench | – | 56.0% |
| GSO-Bench | – | 31.4% |
| LiveBench | – | 78.0% |
| LiveBench Reasoning | – | 88.1% |
| LiveBench Coding | – | 77.5% |
| LiveBench Agentic Coding | – | 53.8% |
| LiveBench Mathematics | – | 94.2% |
| LiveBench Data Analysis | – | 79.3% |
| LiveBench Language | – | 82.6% |
| LiveBench Instruction Following | – | 70.2% |
| AA Intelligence Index | 34.5 | 39.0 |
| IFBench | 79.2% | 74.0% |
| AA-LCR | 79.7% | 82.0% |
| MMMU-Pro | – | 78.4% |
| AA-Omniscience | -14.3 | 5.8 |
| Terminal-Bench Hard | 35.6% | 57.6% |
| GPQA Diamond (AA) | 90.8% | 92.0% |
| Humanity's Last Exam (AA) | 38.5% | 43.7% |
| SciCode (AA) | 50.4% | – |
| τ²-Bench Telecom (AA) | 95.0% | 87.1% |
| AIME (Vals) | – | 96.7% |
| LiveCodeBench | – | 84.1% |
| MMLU-Pro | – | 87.5% |
| LegalBench | – | 86.0% |
| CorpFin | – | 65.3% |
| TaxEval | – | 74.0% |
| MedQA | – | 96.1% |
| SWE-bench (Vals) | – | 78.2% |
| GPQA Diamond (Vals) | – | 91.7% |
| AIME 2026 | 95.8% | 99.2% |
| HMMT February 2026 | 93.9% | 97.7% |
| MathArena Apex | 27.1% | 54.2% |
| SWE-Bench Pro | – | 59.1% |
| MCP Atlas | – | 70.6% |
| ARC-AGI-1 | – | 93.7% |
| ARC-AGI-2 | – | 74.0% |
| CritPt | 16.6% | 23.4% |
| GDPval (AA) | 47.1% | 40.3% |
| τ²-Bench Banking (AA) | 39.4% | 39.6% |
| ITBench SRE (AA) | 31.5% | – |
| Analyst Agent (AA) | 25.0% | – |
| APEX-Agents (AA) | – | 33.3% |
| CaseLaw v2 | – | 63.8% |
| Code Migration | – | 35.0% |
| Harvey's Legal Agent Benchmark | – | 0.0% |
| MedCode | – | 41.3% |
| MedScribe | – | 77.5% |
| MMMU-Pro (Vals) | – | 87.5% |
| MortgageTax | – | 68.3% |
| ProgramBench | – | 0.0% |
| SAGE | – | 43.3% |
| SkillsBench | – | 51.7% |
| Vibe Code Bench v1.1 | – | 67.4% |
| SWE-Bench Pro (private) | – | 43.4% |
| SWE Atlas: Codebase QnA | – | 40.8% |
| SWE Atlas: Refactoring | – | 44.3% |
| SWE Atlas: Test Writing | – | 44.4% |
| Chess Puzzles | – | 44.0% |
| EBR-bench | – | 25.4% |
| Mystery Game Puzzles | – | 37.0% |
| CL-bench | – | 27.9% |
| CL-bench Life | – | 21.7% |
| METR Time Horizons | – | 74.3% |
| DeepSWE | – | 51.8% |
| LMCA | 35.9% | 52.0% |
| DTBench | 86.4% | 94.4% |
Data as of 2026-09-19. Best configuration of each model; every score links to its source on the model pages.
DeepSeek V4 Flash vs GPT-5.4: questions
- Is DeepSeek V4 Flash better than GPT-5.4?
- GPT-5.4 (xhigh) leads on quality: 65.4 vs 62.1. The BenchLeader Index combines every independent quality benchmark; GPT-5.4 (xhigh) is ahead overall as of 2026-09-19, but check the category scores for your use.
- Is DeepSeek V4 Flash better than GPT-5.4 for coding?
- GPT-5.4 scores higher in coding (67 vs 49 on the category index, where 50 is average).
- Is DeepSeek V4 Flash better than GPT-5.4 for agentic tasks?
- DeepSeek V4 Flash scores higher in agentic tasks (67 vs 63 on the category index, where 50 is average).
- Which is cheaper, DeepSeek V4 Flash or GPT-5.4?
- DeepSeek V4 Flash is cheaper: $0.262 against $5.63 per million tokens, blended at three input tokens per output token.
- Which is faster, DeepSeek V4 Flash or GPT-5.4?
- DeepSeek V4 Flash streams faster: 212 against 121 output tokens per second.
- Which has the larger context window?
- GPT-5.4 accepts more context: 1.1M against 1M tokens.