Claude Opus 4.1 vs DeepSeek V3.1 Terminus
Claude Opus 4.1 leads DeepSeek V3.1 Terminus on the Artificial Analysis Intelligence Index, 22.8 to 14.8, and DeepSeek V3.1 Terminus costs 73.9x less per output token ($1.0142 vs $75.00 per million). Updated October 22, 2026; 30 benchmarks have a result for both.
Claude Opus 4.1 or DeepSeek V3.1 Terminus: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick Claude Opus 4.1 for a larger context window (200K against 164K tokens) and work measured by LMArena Text: science or LMArena Text: medicine and healthcare, where it leads.
- Shared results
- 30
- Claude Opus 4.1 only
- 43
- DeepSeek V3.1 Terminus only
- 15
- Like-for-like categories
- 7 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
Neither has a coding score yet.
One side not measured
Intelligence
AA Intelligence Index
Claude Opus 4.1
Claude Opus 4.1 leads, 22.8 against 14.8.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only DeepSeek V3.1 Terminus has a AA Agentic Index result, 6.8.
Directional only
Reasoning
GPQA Diamond
No call
Only Claude Opus 4.1 has a GPQA Diamond result, 76.3%.
Directional only
Math
AIME
No call
Only Claude Opus 4.1 has a AIME result, 78.2%.
Directional only
Knowledge
MMLU Pro
No call
Only Claude Opus 4.1 has a MMLU Pro result, 87.9%.
Directional only
Web design
Design Arena: websites
DeepSeek V3.1 Terminus
DeepSeek V3.1 Terminus leads, 1187 against 1176.
Same board, both measured
Long documents
Listed context window
Claude Opus 4.1
Claude Opus 4.1 takes 200K tokens against 164K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
DeepSeek V3.1 Terminus
Claude Opus 4.1 $0.052, DeepSeek V3.1 Terminus $0.0008 per turn.
List prices
At a glance
- Coding index
- Claude Opus 4.1 not benchmarked, DeepSeek V3.1 Terminus not benchmarked.
- Widest category
- Intelligence, 8.0 points apart on average over 1 shared benchmark.
- Widest single gap
- Design Arena: SVG: Claude Opus 4.1 1152 against DeepSeek V3.1 Terminus 1065, 10.9 points apart on a 0 to 100 scale.
- Output price
- Claude Opus 4.1 $75.00 against DeepSeek V3.1 Terminus $1.0142 per million output tokens, 73.9x apart.
- Context window
- Claude Opus 4.1 takes 200K 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 Opus 4.1 | Bars | DeepSeek V3.1 Terminus | Ties |
|---|---|---|---|---|
| Coding | 2 | 0 | ||
| Intelligence | 1 | 0 | ||
| Reasoning | 2 | 0 | ||
| Math | 1 | 0 | ||
| Knowledge | 0 | 4 | ||
| Web design | 3 | 4 | ||
| General | 9 | 4 | ||
| All shared boards | 18 | 12 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index20
| Benchmark | Claude Opus 4.1 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| LMArena WebDev | 1390 | Not measured | Only Claude Opus 4.1 measured |
| AA Coding Index | Not measured | 43.5 | Only DeepSeek V3.1 Terminus measured |
| LiveCodeBench (Vals AI) | 66.5% | Not measured | Only Claude Opus 4.1 measured |
| LiveCodeBench (Artificial Analysis run) | Not measured | 79.8% | Only DeepSeek V3.1 Terminus measured |
| SciCode | Not measured | 38.0% | Only DeepSeek V3.1 Terminus measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 31.8% | Only DeepSeek V3.1 Terminus measured |
| Terminal-Bench | 38.0% | Not measured | Only Claude Opus 4.1 measured |
| WeirdML | 45.9% | Not measured | Only Claude Opus 4.1 measured |
| Cybench | 42.0% | Not measured | Only Claude Opus 4.1 measured |
| ALE-Bench | Not measured | 745.2 | Only DeepSeek V3.1 Terminus measured |
| LMArena Text: coding | 1479 | 1425 | Claude Opus 4.1 |
| LMArena Text: software and IT | 1456 | 1426 | Claude Opus 4.1 |
| LMArena WebDev: HTML | 1399 | Not measured | Only Claude Opus 4.1 measured |
| SciCode | 4.6% | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 25 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Opus 4.1 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| AA Intelligence Index | 22.8 | 14.8 | Claude Opus 4.1 |
| Epoch Capabilities Index | 144.1 | Not measured | Only Claude Opus 4.1 measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index5 boards, none shared
| Benchmark | Claude Opus 4.1 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 6.8 | Only DeepSeek V3.1 Terminus measured |
| τ²-Bench Telecom | Not measured | 37.1% | Only DeepSeek V3.1 Terminus measured |
| METR time horizons | 66.8% | Not measured | Only Claude Opus 4.1 measured |
| GDPval | 43.6% | Not measured | Only Claude Opus 4.1 measured |
| DeepResearch Bench | 48.3% | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 36 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Opus 4.1 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| GPQA Diamond | 76.3% | Not measured | Only Claude Opus 4.1 measured |
| MMMU Pro (Vals AI) | 77.5% | Not measured | Only Claude Opus 4.1 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 79.2% | Only DeepSeek V3.1 Terminus measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 16.4% | Only DeepSeek V3.1 Terminus measured |
| GPQA Diamond (Epoch AI run) | 77.3% | Not measured | Only Claude Opus 4.1 measured |
| SimpleBench | 60.0% | Not measured | Only Claude Opus 4.1 measured |
| Mystery game puzzles | 21.0% | Not measured | Only Claude Opus 4.1 measured |
| EBR-bench | 7.9% | Not measured | Only Claude Opus 4.1 measured |
| VPCT | 35.0% | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: hard prompts | 1442 | 1426 | Claude Opus 4.1 |
| LMArena Text: expert | 1438 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: hard prompts in English | 1451 | 1432 | Claude Opus 4.1 |
| Kagi LLM Benchmark | Not measured | 57.4% | Only DeepSeek V3.1 Terminus measured |
| Neither model has a result on the other 9 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Opus 4.1 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| AIME | 78.2% | Not measured | Only Claude Opus 4.1 measured |
| MATH 500 (Vals AI) | 95.4% | Not measured | Only Claude Opus 4.1 measured |
| MGSM (Vals AI) | 94.4% | Not measured | Only Claude Opus 4.1 measured |
| 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 | 68.9% | Not measured | Only Claude Opus 4.1 measured |
| FrontierMath, tiers 1 to 3 | 12.6% | Not measured | Only Claude Opus 4.1 measured |
| FrontierMath, tier 4 | 2.4% | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: math | 1431 | 1402 | Claude Opus 4.1 |
| LMArena Text: mathematical work | 1434 | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 3 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index04
| Benchmark | Claude Opus 4.1 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| MMLU Pro | 87.9% | Not measured | Only Claude Opus 4.1 measured |
| LegalBench (Vals AI) | 83.5% | Not measured | Only Claude Opus 4.1 measured |
| TaxEval (Vals AI) | 73.7% | Not measured | Only Claude Opus 4.1 measured |
| MortgageTax (Vals AI) | 61.1% | Not measured | Only Claude Opus 4.1 measured |
| MedQA (Vals AI) | 93.6% | Not measured | Only Claude Opus 4.1 measured |
| MedCode (Vals AI) | 47.2% | Not measured | Only Claude Opus 4.1 measured |
| MMLU Pro (Artificial Analysis run) | Not measured | 85.1% | Only DeepSeek V3.1 Terminus measured |
| LMArena Text: science | 1422 | 1451 | DeepSeek V3.1 Terminus |
| LMArena Text: medicine and healthcare | 1416 | 1468 | DeepSeek V3.1 Terminus |
| LMArena Text: legal and government | 1421 | 1457 | DeepSeek V3.1 Terminus |
| LMArena Text: business and finance | 1406 | 1414 | DeepSeek V3.1 Terminus |
| FACTS Benchmark Suite | 40.4% | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 6 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index34
| Benchmark | Claude Opus 4.1 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| Design Arena: websites | 1176 | 1187 | DeepSeek V3.1 Terminus |
| Design Arena: UI components | 1162 | 1182 | DeepSeek V3.1 Terminus |
| Design Arena: game dev | 1171 | 1131 | Claude Opus 4.1 |
| Design Arena: data viz | 1166 | 1168 | DeepSeek V3.1 Terminus |
| Design Arena: 3D | 1152 | 1141 | Claude Opus 4.1 |
| Design Arena: all code categories | 1170 | 1175 | DeepSeek V3.1 Terminus |
| Design Arena: SVG | 1152 | 1065 | Claude Opus 4.1 |
| Design Arena: ASCII art | 1167 | Not measured | Only Claude Opus 4.1 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index94
| Benchmark | Claude Opus 4.1 | DeepSeek V3.1 Terminus | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 31.4% | Not measured | Only Claude Opus 4.1 measured |
| MedScribe (Vals AI) | 73.9% | Not measured | Only Claude Opus 4.1 measured |
| IFBench | Not measured | 57.0% | Only DeepSeek V3.1 Terminus measured |
| Long context reasoning (AA-LCR) | Not measured | 69.3% | Only DeepSeek V3.1 Terminus measured |
| DTBench | 80.0% | 81.3% | DeepSeek V3.1 Terminus |
| LMCA | 37.1% | 28.6% | Claude Opus 4.1 |
| Creative writing (Lech Mazur) | 84.7% | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text | 1419 | 1419 | Claude Opus 4.1 |
| LMArena Text: instruction following | 1435 | 1404 | Claude Opus 4.1 |
| LMArena Text: creative writing | 1412 | 1403 | Claude Opus 4.1 |
| LMArena Text: English | 1433 | 1429 | Claude Opus 4.1 |
| LMArena Text: non-English | 1405 | 1408 | DeepSeek V3.1 Terminus |
| LMArena Text: Chinese | 1427 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: German | 1413 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: Japanese | 1377 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: Korean | 1381 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: French | 1433 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: Spanish | 1448 | Not measured | Only Claude Opus 4.1 measured |
| LMArena Text: Russian | 1422 | 1435 | DeepSeek V3.1 Terminus |
| LMArena Text: Polish | 1413 | 1427 | DeepSeek V3.1 Terminus |
| LMArena Text: multi-turn | 1444 | 1411 | Claude Opus 4.1 |
| LMArena Text: longer queries | 1455 | 1422 | Claude Opus 4.1 |
| LMArena Text: writing and language | 1418 | 1409 | Claude Opus 4.1 |
| LMArena Text: entertainment and media | 1398 | 1391 | Claude Opus 4.1 |
| Neither model has a result on the other 22 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Opus 4.1 | 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 Opus 4.1 | DeepSeek V3.1 Terminus |
|---|---|---|
| Maker | Anthropic | DeepSeek |
| Weights | No public weights listed | Open weights |
| Released | August 5, 2025 | September 22, 2025 |
| Context window | 200K | 164K |
| Input $/Mtok | $15.00 | $0.3063 |
| Output $/Mtok | $75.00 | $1.0142 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 1 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Opus 4.1 better than DeepSeek V3.1 Terminus for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick Claude Opus 4.1 for a larger context window (200K against 164K tokens) and work measured by LMArena Text: science or LMArena Text: medicine and healthcare, where it leads.
Which is cheaper, Claude Opus 4.1 or DeepSeek V3.1 Terminus?
Claude Opus 4.1 costs $15.00 per million input tokens and $75.00 per million output tokens; DeepSeek V3.1 Terminus costs $0.3063 and $1.0142. Cost per solved task is known for neither of them.
Which has the bigger context window, Claude Opus 4.1 or DeepSeek V3.1 Terminus?
Claude Opus 4.1, with 200K tokens against 164K.
How many benchmarks is the Claude Opus 4.1 vs DeepSeek V3.1 Terminus comparison based on?
30 benchmarks have a result for both models as of October 22, 2026. Claude Opus 4.1's coding index rests on 1 independent benchmark and DeepSeek V3.1 Terminus's on 0. Where only one model has a result, the page says so instead of naming a winner.