Claude Sonnet 5 vs DeepSeek V4 Flash
Claude Sonnet 5 
DeepSeek V4 Flash Verdict
- Claude Sonnet 5 (high) and DeepSeek V4 Flash (max) are level on quality (62.2 vs 62.1).
- Claude Sonnet 5 (high) is stronger in coding, human preference, knowledge, maths, multimodal.
- DeepSeek V4 Flash (max) is stronger in agents & tools, composite, long context, reasoning, instruction following.
- DeepSeek V4 Flash (max) is 15× cheaper ($0.262 vs $4.00 per 1M blended).
- DeepSeek V4 Flash (max) streams 3.3× faster (212 vs 64 tokens per second).
| Metric | Claude Sonnet 5 (high) | DeepSeek V4 Flash (max) |
|---|---|---|
| BenchLeader Index | 62.2 | 62.1 |
| Agents & tools score | 62.0 | 67.0 |
| Coding score | 61.5 | 49.1 |
| Composite score | 69.6 | 72.8 |
| Human preference score | 65.9 | – |
| Knowledge score | 62.4 | 57.4 |
| Long context score | 64.7 | 66.3 |
| Maths score | 66.9 | 57.3 |
| Multimodal score | 62.6 | – |
| Reasoning score | 69.6 | 73.9 |
| Instruction following score | – | 76.7 |
| Blended price $/M | $4.00 | $0.262 |
| Output speed | 64 tok/s | 212 tok/s |
| Time to first answer | 2.9 s | 10.6 s |
| Context window | 1M | 1M |
| SciCode | 48.6% | 44.9% |
| WeirdML | 68.8% | 45.6% |
| LMArena Text | 1461 | – |
| LMArena Hard Prompts | 1489 | – |
| LMArena Coding | 1521 | – |
| LMArena WebDev | 1537 | – |
| LMArena Vision | 1277 | – |
| LMArena Agent | 6 | – |
| AA Intelligence Index | 32.0 | 34.5 |
| IFBench | – | 79.2% |
| AA-LCR | 76.7% | 79.7% |
| AA-Omniscience | -3.7 | -14.3 |
| Terminal-Bench Hard | – | 35.6% |
| GPQA Diamond (AA) | – | 90.8% |
| Humanity's Last Exam (AA) | 35.7% | 38.5% |
| SciCode (AA) | 54.3% | 50.4% |
| τ²-Bench Telecom (AA) | – | 95.0% |
| AIME 2026 | – | 95.8% |
| HMMT February 2026 | – | 93.9% |
| MathArena Apex | – | 27.1% |
| CritPt | 15.1% | 16.6% |
| GDPval (AA) | 40.4% | 47.1% |
| τ²-Bench Banking (AA) | – | 39.4% |
| ITBench SRE (AA) | – | 31.5% |
| Analyst Agent (AA) | – | 25.0% |
| LMArena Maths | 1476 | – |
| LMArena Creative Writing | 1437 | – |
| LMArena Instruction Following | 1465 | – |
| LMArena Multi-turn | 1473 | – |
| LMArena Longer Queries | 1482 | – |
| LMArena Document | 1476 | – |
| DeepSWE | 48.2% | – |
| LMCA | – | 35.9% |
| DTBench | – | 86.4% |
| CursorBench | 56.9% | – |
| ALE-Bench | 1463.1 | – |
Data as of 2026-09-19. Best configuration of each model; every score links to its source on the model pages.
Claude Sonnet 5 vs DeepSeek V4 Flash: questions
- Is Claude Sonnet 5 better than DeepSeek V4 Flash?
- Claude Sonnet 5 (high) and DeepSeek V4 Flash (max) are level on quality (62.2 vs 62.1). The BenchLeader Index combines every independent quality benchmark; Claude Sonnet 5 (high) is ahead overall as of 2026-09-19, but check the category scores for your use.
- Is Claude Sonnet 5 better than DeepSeek V4 Flash for coding?
- Claude Sonnet 5 scores higher in coding (62 vs 49 on the category index, where 50 is average).
- Is Claude Sonnet 5 better than DeepSeek V4 Flash for agentic tasks?
- DeepSeek V4 Flash scores higher in agentic tasks (67 vs 62 on the category index, where 50 is average).
- Which is cheaper, Claude Sonnet 5 or DeepSeek V4 Flash?
- DeepSeek V4 Flash is cheaper: $0.262 against $4.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Sonnet 5 or DeepSeek V4 Flash?
- DeepSeek V4 Flash streams faster: 212 against 64 output tokens per second.
- Which has the larger context window?
- Both accept 1M tokens of context.