Claude Sonnet 5.5 vs DeepSeek V4 Flash Vision Exp
Claude Sonnet 5.5 leads DeepSeek V4 Flash Vision Exp on the Artificial Analysis Intelligence Index, 56.0 to 34.8, and DeepSeek V4 Flash Vision Exp costs 7.6x less per output token ($1.32 vs $10.00 per million). Updated October 22, 2026; 11 benchmarks have a result for both.
Claude Sonnet 5.5 or DeepSeek V4 Flash Vision Exp: which to pick
Only Claude Sonnet 5.5 has a coding score, 87.3 on the Vibe Coding Index; DeepSeek V4 Flash Vision Exp has none, so the two cannot be ranked on coding.
Pick DeepSeek V4 Flash Vision Exp for output tokens 7.6x cheaper ($1.32 vs $10.00 per million) and a larger context window (1.05M against 1M tokens).
- Shared results
- 11
- Claude Sonnet 5.5 only
- 85
- DeepSeek V4 Flash Vision Exp only
- 3
- Like-for-like categories
- 6 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 5.5 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Claude Sonnet 5.5
Claude Sonnet 5.5 leads, 56.0 against 34.8.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only DeepSeek V4 Flash Vision Exp has a AA Agentic Index result, 47.5.
Directional only
Web design
Design Arena: websites
No call
Only Claude Sonnet 5.5 has a Design Arena: websites result, 1326.
Directional only
General
Vals Index
No call
Only Claude Sonnet 5.5 has a Vals Index result, 70.8%.
Directional only
Long documents
Listed context window
DeepSeek V4 Flash Vision Exp
DeepSeek V4 Flash Vision Exp takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
DeepSeek V4 Flash Vision Exp
Claude Sonnet 5.5 $0.0070, DeepSeek V4 Flash Vision Exp $0.0011 per turn.
List prices
At a glance
- Coding index
- Claude Sonnet 5.5 87.3 from 5 benchmarks, DeepSeek V4 Flash Vision Exp not benchmarked.
- Widest category
- Coding, 34.2 points apart on average over 2 shared benchmarks.
- Widest single gap
- LiveBench coding: Claude Sonnet 5.5 94.7% against DeepSeek V4 Flash Vision Exp 37.6%, 57.1 points apart on a 0 to 100 scale.
- Output price
- Claude Sonnet 5.5 $10.00 against DeepSeek V4 Flash Vision Exp $1.32 per million output tokens, 7.6x apart.
- Context window
- Claude Sonnet 5.5 takes 1M tokens, DeepSeek V4 Flash Vision Exp 1.05M.
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 5.5 | Bars | DeepSeek V4 Flash Vision Exp | Ties |
|---|---|---|---|---|
| Coding | 2 | 0 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 3 | 0 | ||
| Reasoning | 2 | 0 | ||
| Web design | 1 | 0 | ||
| General | 1 | 1 | ||
| All shared boards | 10 | 1 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index20
| Benchmark | Claude Sonnet 5.5 | DeepSeek V4 Flash Vision Exp | Leader |
|---|---|---|---|
| LiveBench coding | 94.7% | 37.6% | Claude Sonnet 5.5 |
| LMArena WebDev | 1768 | Not measured | Only Claude Sonnet 5.5 measured |
| AA Coding Index | Not measured | 65.0 | Only DeepSeek V4 Flash Vision Exp measured |
| Terminal-Bench 4 (Vals AI) | 64.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Vibe Code Bench (Vals AI) | 92.4% | Not measured | Only Claude Sonnet 5.5 measured |
| Code migration (Vals AI) | 69.8% | Not measured | Only Claude Sonnet 5.5 measured |
| ProgramBench (Vals AI) | 6.5% | Not measured | Only Claude Sonnet 5.5 measured |
| IOI (Vals AI) | 83.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Terminal-Bench 2.1 (Vals AI) | 83.2% | Not measured | Only Claude Sonnet 5.5 measured |
| SWE-bench Multimodal (Vals AI) | 58.3% | Not measured | Only Claude Sonnet 5.5 measured |
| CyberBench (Vals AI) | 59.6% | Not measured | Only Claude Sonnet 5.5 measured |
| SciCode | 61.0% | 49.7% | Claude Sonnet 5.5 |
| FrontierCode | 52.1% | Not measured | Only Claude Sonnet 5.5 measured |
| FrontierSWE | 61.9% | Not measured | Only Claude Sonnet 5.5 measured |
| ALE-Bench | 1819.1 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: coding | 1513 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: software and IT | 1504 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena WebDev: React | 1817 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena WebDev: HTML | 1741 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena WebDev: from an image | 1737 | Not measured | Only Claude Sonnet 5.5 measured |
| SciCode | 13.8% | Not measured | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 18 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Sonnet 5.5 | DeepSeek V4 Flash Vision Exp | Leader |
|---|---|---|---|
| AA Intelligence Index | 56.0 | 34.8 | Claude Sonnet 5.5 |
| Epoch Capabilities Index | 166.2 | Not measured | Only Claude Sonnet 5.5 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Claude Sonnet 5.5 | DeepSeek V4 Flash Vision Exp | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 47.5 | Only DeepSeek V4 Flash Vision Exp measured |
| Design Arena: agents building web apps | 1305 | Not measured | Only Claude Sonnet 5.5 measured |
| Design Arena: agents building mobile apps | 1260 | Not measured | Only Claude Sonnet 5.5 measured |
| Design Arena: spreadsheets | 1260 | Not measured | Only Claude Sonnet 5.5 measured |
| LiveBench research | 83.6% | 69.2% | Claude Sonnet 5.5 |
| LiveBench browser | 84.0% | 64.0% | Claude Sonnet 5.5 |
| LiveBench long agentic | 78.8% | 39.0% | Claude Sonnet 5.5 |
| SREBench (Vals AI) | 30.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Finance Agent (Vals AI) | 58.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Tax Agent Bench (Vals AI) | 42.0% | Not measured | Only Claude Sonnet 5.5 measured |
| Legal Research Bench (Vals AI) | 48.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Harvey's Legal Agent Benchmark (Vals AI) | 10.4% | Not measured | Only Claude Sonnet 5.5 measured |
| Excel Modeling Benchmark (Vals AI) | 75.7% | Not measured | Only Claude Sonnet 5.5 measured |
| BioMysteryBench (Vals AI) | 81.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Terminal-Bench-Science (Vals AI) | 47.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Vals Science Index | 59.1% | Not measured | Only Claude Sonnet 5.5 measured |
| APEX-Agents | 75.5% | Not measured | Only Claude Sonnet 5.5 measured |
| SpireClimb | 1.3% | Not measured | Only Claude Sonnet 5.5 measured |
| Vending-Bench 2 | $11,165 | Not measured | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 22 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Sonnet 5.5 | DeepSeek V4 Flash Vision Exp | Leader |
|---|---|---|---|
| LiveBench reasoning | 91.6% | 85.4% | Claude Sonnet 5.5 |
| MysteryMechanism (Vals AI) | 49.1% | Not measured | Only Claude Sonnet 5.5 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 91.3% | Only DeepSeek V4 Flash Vision Exp measured |
| Humanity's Last Exam (Artificial Analysis run) | 55.0% | 34.5% | Claude Sonnet 5.5 |
| GPQA Diamond (Epoch AI run) | 95.6% | Not measured | Only Claude Sonnet 5.5 measured |
| Chess puzzles | 59.0% | Not measured | Only Claude Sonnet 5.5 measured |
| Mystery game puzzles | 65.0% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: hard prompts | 1494 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: expert | 1531 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: hard prompts in English | 1502 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Vision: diagrams | 1329 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Vision: homework | 1331 | Not measured | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 10 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Claude Sonnet 5.5 | DeepSeek V4 Flash Vision Exp | Leader |
|---|---|---|---|
| OTIS Mock AIME | 100.0% | Not measured | Only Claude Sonnet 5.5 measured |
| FrontierMath, tiers 1 to 3 | 88.8% | Not measured | Only Claude Sonnet 5.5 measured |
| FrontierMath, tier 4 | 80.5% | Not measured | Only Claude Sonnet 5.5 measured |
| ProofBench | 100.0% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: math | 1497 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: mathematical work | 1510 | Not measured | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Claude Sonnet 5.5 | DeepSeek V4 Flash Vision Exp | Leader |
|---|---|---|---|
| MedCode (Vals AI) | 52.9% | Not measured | Only Claude Sonnet 5.5 measured |
| SimpleQA Verified | 46.5% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: science | 1483 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: medicine and healthcare | 1464 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: legal and government | 1483 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: business and finance | 1468 | Not measured | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 12 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Sonnet 5.5 | DeepSeek V4 Flash Vision Exp | Leader |
|---|---|---|---|
| Design Arena: websites | 1326 | Not measured | Only Claude Sonnet 5.5 measured |
| Design Arena: UI components | 1368 | Not measured | Only Claude Sonnet 5.5 measured |
| Design Arena: game dev | 1471 | Not measured | Only Claude Sonnet 5.5 measured |
| Design Arena: data viz | 1392 | Not measured | Only Claude Sonnet 5.5 measured |
| Design Arena: 3D | 1445 | Not measured | Only Claude Sonnet 5.5 measured |
| Design Arena: all code categories | 1364 | Not measured | Only Claude Sonnet 5.5 measured |
| LiveBench design | 85.0% | 70.7% | Claude Sonnet 5.5 |
| Neither model has a result on the other 2 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index11
| Benchmark | Claude Sonnet 5.5 | DeepSeek V4 Flash Vision Exp | Leader |
|---|---|---|---|
| Vals Index | 70.8% | Not measured | Only Claude Sonnet 5.5 measured |
| LiveBench data analysis | 59.5% | 79.5% | DeepSeek V4 Flash Vision Exp |
| Public Benefits Bench (Vals AI) | 67.2% | Not measured | Only Claude Sonnet 5.5 measured |
| SAGE (Vals AI) | 51.8% | Not measured | Only Claude Sonnet 5.5 measured |
| MedScribe (Vals AI) | 91.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Long context reasoning (AA-LCR) | 82.7% | 81.3% | Claude Sonnet 5.5 |
| DTBench | 97.3% | Not measured | Only Claude Sonnet 5.5 measured |
| LMCA | 68.3% | Not measured | Only Claude Sonnet 5.5 measured |
| Furniture assembly | 75.0% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text | 1473 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: instruction following | 1492 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: creative writing | 1467 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Vision | 1287 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: English | 1484 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: non-English | 1456 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: Chinese | 1535 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: French | 1499 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: Spanish | 1451 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: Russian | 1454 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: multi-turn | 1465 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: longer queries | 1495 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: writing and language | 1474 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: entertainment and media | 1461 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Vision: English | 1289 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Vision: reading text | 1297 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Vision: creative writing | 1242 | Not measured | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 20 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Sonnet 5.5 | DeepSeek V4 Flash Vision Exp | 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 V4 Flash Vision Exp costs less
Repository review
50K input + 3K output tokens
DeepSeek V4 Flash Vision Exp costs less
Agent loop
200K input + 10K output tokens
DeepSeek V4 Flash Vision Exp 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 5.5 | DeepSeek V4 Flash Vision Exp |
|---|---|---|
| Maker | Anthropic | DeepSeek |
| Weights | No public weights listed | Open weights |
| Released | September 28, 2026 | August 21, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $2.00 | $0.44 |
| Output $/Mtok | $10.00 | $1.32 |
| Coding index | 87.3 | Not benchmarked |
| Independent measurements behind it | 5 | 1 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Sonnet 5.5 better than DeepSeek V4 Flash Vision Exp for coding?
Only Claude Sonnet 5.5 has a coding score, 87.3 on the Vibe Coding Index; DeepSeek V4 Flash Vision Exp has none, so the two cannot be ranked on coding. Pick DeepSeek V4 Flash Vision Exp for output tokens 7.6x cheaper ($1.32 vs $10.00 per million) and a larger context window (1.05M against 1M tokens).
Which is cheaper, Claude Sonnet 5.5 or DeepSeek V4 Flash Vision Exp?
Claude Sonnet 5.5 costs $2.00 per million input tokens and $10.00 per million output tokens; DeepSeek V4 Flash Vision Exp costs $0.44 and $1.32. Cost per solved task is known for neither of them.
Which has the bigger context window, Claude Sonnet 5.5 or DeepSeek V4 Flash Vision Exp?
DeepSeek V4 Flash Vision Exp, with 1.05M tokens against 1M.
How many benchmarks is the Claude Sonnet 5.5 vs DeepSeek V4 Flash Vision Exp comparison based on?
11 benchmarks have a result for both models as of October 22, 2026. Claude Sonnet 5.5's coding index rests on 5 independent benchmarks and DeepSeek V4 Flash Vision Exp's on 1. Where only one model has a result, the page says so instead of naming a winner.