Claude Sonnet 5 vs DeepSeek V3.1 Terminus
Claude Sonnet 5 leads DeepSeek V3.1 Terminus on the Artificial Analysis Intelligence Index, 38.2 to 14.8, and DeepSeek V3.1 Terminus costs 9.9x less per output token ($1.0142 vs $10.00 per million). Updated October 22, 2026; 37 benchmarks have a result for both.
Claude Sonnet 5 or DeepSeek V3.1 Terminus: which to pick
Only Claude Sonnet 5 has a coding score, 57.7 on the Vibe Coding Index; DeepSeek V3.1 Terminus has none, so the two cannot be ranked on coding.
Pick DeepSeek V3.1 Terminus for output tokens 9.9x cheaper ($1.0142 vs $10.00 per million) and work measured by LMArena Text: medicine and healthcare or LMArena Text: legal and government, where it leads.
- Shared results
- 37
- Claude Sonnet 5 only
- 84
- DeepSeek V3.1 Terminus only
- 8
- Like-for-like categories
- 8 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Only Claude Sonnet 5 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Claude Sonnet 5
Claude Sonnet 5 leads, 38.2 against 14.8.
Same board, both measured
Agentic work
AA Agentic Index
Claude Sonnet 5
Claude Sonnet 5 leads, 43.6 against 6.8.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only Claude Sonnet 5 has a GPQA Diamond result, 88.9%.
Directional only
Knowledge
MMLU Pro
No call
Only Claude Sonnet 5 has a MMLU Pro result, 87.5%.
Directional only
Web design
Design Arena: websites
Claude Sonnet 5
Claude Sonnet 5 leads, 1274 against 1187.
Same board, both measured
Long documents
Listed context window
Claude Sonnet 5
Claude Sonnet 5 takes 1M tokens against 164K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
DeepSeek V3.1 Terminus
Claude Sonnet 5 $0.0070, DeepSeek V3.1 Terminus $0.0008 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Claude Sonnet 5 has the number, $1.87.
Directional only
At a glance
- Coding index
- Claude Sonnet 5 57.7 from 6 benchmarks, DeepSeek V3.1 Terminus not benchmarked.
- Widest category
- Agentic work, 36.8 points apart on average over 1 shared benchmark.
- Widest single gap
- AA Agentic Index: Claude Sonnet 5 43.6 against DeepSeek V3.1 Terminus 6.8, 36.8 points apart on a 0 to 100 scale.
- Output price
- Claude Sonnet 5 $10.00 against DeepSeek V3.1 Terminus $1.0142 per million output tokens, 9.9x apart.
- Context window
- Claude Sonnet 5 takes 1M tokens, DeepSeek V3.1 Terminus 164K.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Claude Sonnet 5 | Bars | DeepSeek V3.1 Terminus | Ties |
|---|---|---|---|---|
| Coding | 5 | 0 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 4 | 0 | ||
| Math | 1 | 0 | ||
| Knowledge | 2 | 2 | ||
| Web design | 7 | 0 | ||
| General | 13 | 1 | ||
| All shared boards | 34 | 3 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index50
| Benchmark | Claude Sonnet 5 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| LiveBench coding | 74.7% | Not measured | Only Claude Sonnet 5 measured |
| LMArena WebDev | 1540 | Not measured | Only Claude Sonnet 5 measured |
| AA Coding Index | 71.5 | 43.5 | Claude Sonnet 5 |
| LiveCodeBench (Vals AI) | 82.4% | Not measured | Only Claude Sonnet 5 measured |
| SWE-bench Verified (Vals AI) | 79.6% | Not measured | Only Claude Sonnet 5 measured |
| Terminal-Bench 4 (Vals AI) | 10.6% | Not measured | Only Claude Sonnet 5 measured |
| Vibe Code Bench (Vals AI) | 81.3% | Not measured | Only Claude Sonnet 5 measured |
| Code migration (Vals AI) | 44.4% | Not measured | Only Claude Sonnet 5 measured |
| ProgramBench (Vals AI) | 0.0% | Not measured | Only Claude Sonnet 5 measured |
| IOI (Vals AI) | 45.0% | Not measured | Only Claude Sonnet 5 measured |
| Terminal-Bench 2.1 (Vals AI) | 74.5% | Not measured | Only Claude Sonnet 5 measured |
| Vibe Code Bench 1-100 (Vals AI) | 13.8% | Not measured | Only Claude Sonnet 5 measured |
| SkillsBench (Vals AI) | 46.5% | Not measured | Only Claude Sonnet 5 measured |
| CyberBench (Vals AI) | 70.3% | Not measured | Only Claude Sonnet 5 measured |
| LiveCodeBench (Artificial Analysis run) | Not measured | 79.8% | Only DeepSeek V3.1 Terminus measured |
| SciCode | 54.3% | 38.0% | Claude Sonnet 5 |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 31.8% | Only DeepSeek V3.1 Terminus measured |
| FrontierCode | 42.7% | Not measured | Only Claude Sonnet 5 measured |
| GSO-Bench | 37.3% | Not measured | Only Claude Sonnet 5 measured |
| WeirdML | 68.8% | Not measured | Only Claude Sonnet 5 measured |
| ALE-Bench | 1463.1 | 745.2 | Claude Sonnet 5 |
| LMArena Text: coding | 1483 | 1425 | Claude Sonnet 5 |
| LMArena Text: software and IT | 1474 | 1426 | Claude Sonnet 5 |
| LMArena WebDev: React | 1541 | Not measured | Only Claude Sonnet 5 measured |
| LMArena WebDev: HTML | 1527 | Not measured | Only Claude Sonnet 5 measured |
| LMArena WebDev: from an image | 1540 | Not measured | Only Claude Sonnet 5 measured |
| SciCode | 10.7% | Not measured | Only Claude Sonnet 5 measured |
| Neither model has a result on the other 12 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Sonnet 5 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| AA Intelligence Index | 38.2 | 14.8 | Claude Sonnet 5 |
| Epoch Capabilities Index | 156.9 | Not measured | Only Claude Sonnet 5 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Sonnet 5 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| AA Agentic Index | 43.6 | 6.8 | Claude Sonnet 5 |
| Design Arena: agents building web apps | 1245 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: agents building full-stack apps | 1249 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: agents building mobile apps | 1215 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: agents building Android apps | 1227 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: agents building Godot games | 1225 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: agents building games | 1227 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: HTML slides | 1168 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: PowerPoint slides | 1191 | Not measured | Only Claude Sonnet 5 measured |
| Design Arena: spreadsheets | 1035 | Not measured | Only Claude Sonnet 5 measured |
| LiveBench research | 82.8% | Not measured | Only Claude Sonnet 5 measured |
| LiveBench browser | 72.0% | Not measured | Only Claude Sonnet 5 measured |
| LiveBench long agentic | 39.0% | Not measured | Only Claude Sonnet 5 measured |
| SREBench (Vals AI) | 0.4% | Not measured | Only Claude Sonnet 5 measured |
| Finance Agent (Vals AI) | 53.9% | Not measured | Only Claude Sonnet 5 measured |
| Tax Agent Bench (Vals AI) | 29.4% | Not measured | Only Claude Sonnet 5 measured |
| Legal Research Bench (Vals AI) | 41.8% | Not measured | Only Claude Sonnet 5 measured |
| Excel Modeling Benchmark (Vals AI) | 66.3% | Not measured | Only Claude Sonnet 5 measured |
| Terminal-Bench-Science (Vals AI) | 5.7% | Not measured | Only Claude Sonnet 5 measured |
| τ²-Bench Telecom | Not measured | 37.1% | Only DeepSeek V3.1 Terminus measured |
| APEX-Agents | 54.5% | Not measured | Only Claude Sonnet 5 measured |
| Vending-Bench 2 | $6,378 | Not measured | Only Claude Sonnet 5 measured |
| Neither model has a result on the other 19 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Claude Sonnet 5 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| GPQA Diamond | 88.9% | Not measured | Only Claude Sonnet 5 measured |
| LiveBench reasoning | 88.7% | Not measured | Only Claude Sonnet 5 measured |
| MMMU Pro (Vals AI) | 83.0% | Not measured | Only Claude Sonnet 5 measured |
| GPQA Diamond (Artificial Analysis run) | 91.1% | 79.2% | Claude Sonnet 5 |
| Humanity's Last Exam (Artificial Analysis run) | 41.3% | 16.4% | Claude Sonnet 5 |
| GPQA Diamond (Epoch AI run) | 90.5% | Not measured | Only Claude Sonnet 5 measured |
| SimpleBench | 60.6% | Not measured | Only Claude Sonnet 5 measured |
| Chess puzzles | 45.0% | Not measured | Only Claude Sonnet 5 measured |
| Mystery game puzzles | 35.0% | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: hard prompts | 1461 | 1426 | Claude Sonnet 5 |
| LMArena Text: expert | 1489 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: hard prompts in English | 1464 | 1432 | Claude Sonnet 5 |
| LMArena Vision: diagrams | 1293 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: homework | 1311 | Not measured | Only Claude Sonnet 5 measured |
| Kagi LLM Benchmark | Not measured | 57.4% | Only DeepSeek V3.1 Terminus measured |
| Neither model has a result on the other 7 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Sonnet 5 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| AA Math Index | Not measured | 89.7 | Only DeepSeek V3.1 Terminus measured |
| AIME 2025 (Artificial Analysis run) | Not measured | 89.7% | Only DeepSeek V3.1 Terminus measured |
| OTIS Mock AIME | 94.7% | Not measured | Only Claude Sonnet 5 measured |
| FrontierMath, tiers 1 to 3 | 65.6% | Not measured | Only Claude Sonnet 5 measured |
| FrontierMath, tier 4 | 29.3% | Not measured | Only Claude Sonnet 5 measured |
| ProofBench | 77.0% | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: math | 1467 | 1402 | Claude Sonnet 5 |
| LMArena Text: mathematical work | 1481 | Not measured | Only Claude Sonnet 5 measured |
| Neither model has a result on the other 5 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index22
| Benchmark | Claude Sonnet 5 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| MMLU Pro | 87.5% | Not measured | Only Claude Sonnet 5 measured |
| LegalBench (Vals AI) | 83.9% | Not measured | Only Claude Sonnet 5 measured |
| CorpFin (Vals AI) | 67.0% | Not measured | Only Claude Sonnet 5 measured |
| TaxEval (Vals AI) | 75.6% | Not measured | Only Claude Sonnet 5 measured |
| MortgageTax (Vals AI) | 70.0% | Not measured | Only Claude Sonnet 5 measured |
| MedCode (Vals AI) | 47.5% | Not measured | Only Claude Sonnet 5 measured |
| MMLU Pro (Artificial Analysis run) | Not measured | 85.1% | Only DeepSeek V3.1 Terminus measured |
| SimpleQA Verified | 33.7% | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: science | 1460 | 1451 | Claude Sonnet 5 |
| LMArena Text: medicine and healthcare | 1442 | 1468 | DeepSeek V3.1 Terminus |
| LMArena Text: legal and government | 1454 | 1457 | DeepSeek V3.1 Terminus |
| LMArena Text: business and finance | 1436 | 1414 | Claude Sonnet 5 |
| Neither model has a result on the other 6 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index70
| Benchmark | Claude Sonnet 5 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| Design Arena: websites | 1274 | 1187 | Claude Sonnet 5 |
| Design Arena: UI components | 1277 | 1182 | Claude Sonnet 5 |
| Design Arena: game dev | 1277 | 1131 | Claude Sonnet 5 |
| Design Arena: data viz | 1251 | 1168 | Claude Sonnet 5 |
| Design Arena: 3D | 1261 | 1141 | Claude Sonnet 5 |
| Design Arena: all code categories | 1275 | 1175 | Claude Sonnet 5 |
| Design Arena: SVG | 1192 | 1065 | Claude Sonnet 5 |
| Design Arena: ASCII art | 1207 | Not measured | Only Claude Sonnet 5 measured |
| LiveBench design | 82.0% | Not measured | Only Claude Sonnet 5 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index131
| Benchmark | Claude Sonnet 5 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| LiveBench data analysis | 71.7% | Not measured | Only Claude Sonnet 5 measured |
| Public Benefits Bench (Vals AI) | 66.0% | Not measured | Only Claude Sonnet 5 measured |
| SAGE (Vals AI) | 48.9% | Not measured | Only Claude Sonnet 5 measured |
| MedScribe (Vals AI) | 76.0% | Not measured | Only Claude Sonnet 5 measured |
| Vals Multimodal Index | 68.8% | Not measured | Only Claude Sonnet 5 measured |
| IFBench | Not measured | 57.0% | Only DeepSeek V3.1 Terminus measured |
| Long context reasoning (AA-LCR) | 82.0% | 69.3% | Claude Sonnet 5 |
| DTBench | 92.5% | 81.3% | Claude Sonnet 5 |
| LMCA | 50.0% | 28.6% | Claude Sonnet 5 |
| Surface Evolver Bench | 60.0% | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text | 1442 | 1419 | Claude Sonnet 5 |
| LMArena Text: instruction following | 1452 | 1404 | Claude Sonnet 5 |
| LMArena Text: creative writing | 1416 | 1403 | Claude Sonnet 5 |
| LMArena Vision | 1273 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: English | 1450 | 1429 | Claude Sonnet 5 |
| LMArena Text: non-English | 1431 | 1408 | Claude Sonnet 5 |
| LMArena Text: Chinese | 1478 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: German | 1442 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: Japanese | 1422 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: Korean | 1412 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: French | 1463 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: Spanish | 1438 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Text: Russian | 1450 | 1435 | Claude Sonnet 5 |
| LMArena Text: Polish | 1425 | 1427 | DeepSeek V3.1 Terminus |
| LMArena Text: multi-turn | 1453 | 1411 | Claude Sonnet 5 |
| LMArena Text: longer queries | 1462 | 1422 | Claude Sonnet 5 |
| LMArena Text: writing and language | 1436 | 1409 | Claude Sonnet 5 |
| LMArena Text: entertainment and media | 1411 | 1391 | Claude Sonnet 5 |
| LMArena Vision: English | 1275 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: Chinese | 1331 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: reading text | 1288 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: humor | 1261 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Vision: creative writing | 1246 | Not measured | Only Claude Sonnet 5 measured |
| LMArena Document | 1466 | Not measured | Only Claude Sonnet 5 measured |
| Neither model has a result on the other 12 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Sonnet 5 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
DeepSeek V3.1 Terminus costs less
Repository review
50K input + 3K output tokens
DeepSeek V3.1 Terminus costs less
Agent loop
200K input + 10K output tokens
DeepSeek V3.1 Terminus costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | Anthropic Claude Sonnet 5 | DeepSeek V3.1 Terminus |
|---|---|---|
| Maker | Anthropic | DeepSeek |
| Weights | No public weights listed | Open weights |
| Released | June 30, 2026 | September 22, 2025 |
| Context window | 1M | 164K |
| Input $/Mtok | $2.00 | $0.3063 |
| Output $/Mtok | $10.00 | $1.0142 |
| Coding index | 57.7 | Not benchmarked |
| Independent measurements behind it | 6 | 0 |
| Cost per solved task | $1.87 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Sonnet 5 better than DeepSeek V3.1 Terminus for coding?
Only Claude Sonnet 5 has a coding score, 57.7 on the Vibe Coding Index; DeepSeek V3.1 Terminus has none, so the two cannot be ranked on coding. Pick DeepSeek V3.1 Terminus for output tokens 9.9x cheaper ($1.0142 vs $10.00 per million) and work measured by LMArena Text: medicine and healthcare or LMArena Text: legal and government, where it leads.
Which is cheaper, Claude Sonnet 5 or DeepSeek V3.1 Terminus?
Claude Sonnet 5 costs $2.00 per million input tokens and $10.00 per million output tokens; DeepSeek V3.1 Terminus costs $0.3063 and $1.0142. Cost per solved task is known for Claude Sonnet 5 only.
Which has the bigger context window, Claude Sonnet 5 or DeepSeek V3.1 Terminus?
Claude Sonnet 5, with 1M tokens against 164K.
How many benchmarks is the Claude Sonnet 5 vs DeepSeek V3.1 Terminus comparison based on?
37 benchmarks have a result for both models as of October 22, 2026. Claude Sonnet 5's coding index rests on 6 independent benchmarks and DeepSeek V3.1 Terminus's on 0. Where only one model has a result, the page says so instead of naming a winner.