DeepSeek V4 Flash 0423 vs Mercury 2
DeepSeek V4 Flash 0423 leads Mercury 2 on the Artificial Analysis Intelligence Index, 24.4 to 10.8, and DeepSeek V4 Flash 0423 costs 2.7x less per output token ($0.28 vs $0.75 per million). Updated October 22, 2026; 35 benchmarks have a result for both.
DeepSeek V4 Flash 0423 or Mercury 2: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick DeepSeek V4 Flash 0423 for output tokens 2.7x cheaper ($0.28 vs $0.75 per million) and a larger context window (1.05M against 128K tokens).
- Shared results
- 35
- DeepSeek V4 Flash 0423 only
- 15
- Mercury 2 only
- 7
- 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
DeepSeek V4 Flash 0423
DeepSeek V4 Flash 0423 leads, 24.4 against 10.8.
Same board, both measured
Agentic work
AA Agentic Index
DeepSeek V4 Flash 0423
DeepSeek V4 Flash 0423 leads, 26.3 against 1.6.
Same board, both measured
Web design
Design Arena: websites
DeepSeek V4 Flash 0423
DeepSeek V4 Flash 0423 leads, 1207 against 1035.
Same board, both measured
Long documents
Listed context window
DeepSeek V4 Flash 0423
DeepSeek V4 Flash 0423 takes 1.05M tokens against 128K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
DeepSeek V4 Flash 0423
DeepSeek V4 Flash 0423 $0.0003, Mercury 2 $0.0006 per turn.
List prices
At a glance
- Coding index
- DeepSeek V4 Flash 0423 not benchmarked, Mercury 2 not benchmarked.
- Widest category
- Coding, 29.3 points apart on average over 8 shared benchmarks.
- Widest single gap
- LMArena WebDev: React: DeepSeek V4 Flash 0423 1585 against Mercury 2 1160, 70.9 points apart on a 0 to 100 scale.
- Output price
- DeepSeek V4 Flash 0423 $0.28 against Mercury 2 $0.75 per million output tokens, 2.7x apart.
- Context window
- DeepSeek V4 Flash 0423 takes 1.05M tokens, Mercury 2 128K.
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 | DeepSeek V4 Flash 0423 | Bars | Mercury 2 | Ties |
|---|---|---|---|---|
| Coding | 7 | 1 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 3 | 0 | ||
| Knowledge | 3 | 0 | ||
| Web design | 8 | 0 | ||
| General | 11 | 0 | ||
| All shared boards | 34 | 1 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index71
| Benchmark | DeepSeek V4 Flash 0423 | Mercury 2 | Leader |
|---|---|---|---|
| LMArena WebDev | 1582 | 1171 | DeepSeek V4 Flash 0423 |
| AA Coding Index | 52.0 | 31.1 | DeepSeek V4 Flash 0423 |
| SciCode | Not measured | 37.7% | Only Mercury 2 measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 26.5% | Only Mercury 2 measured |
| WeirdML | 45.6% | 43.2% | DeepSeek V4 Flash 0423 |
| ALE-Bench | 678.2 | 785.6 | Mercury 2 |
| LMArena Text: coding | 1457 | 1390 | DeepSeek V4 Flash 0423 |
| LMArena Text: software and IT | 1453 | 1385 | DeepSeek V4 Flash 0423 |
| LMArena WebDev: React | 1585 | 1160 | DeepSeek V4 Flash 0423 |
| LMArena WebDev: HTML | 1558 | 1199 | DeepSeek V4 Flash 0423 |
| Neither model has a result on the other 33 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | DeepSeek V4 Flash 0423 | Mercury 2 | Leader |
|---|---|---|---|
| AA Intelligence Index | 24.4 | 10.8 | DeepSeek V4 Flash 0423 |
| Epoch Capabilities Index | 146.1 | Not measured | Only DeepSeek V4 Flash 0423 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | DeepSeek V4 Flash 0423 | Mercury 2 | Leader |
|---|---|---|---|
| AA Agentic Index | 26.3 | 1.6 | DeepSeek V4 Flash 0423 |
| τ²-Bench Telecom | Not measured | 70.8% | Only Mercury 2 measured |
| Neither model has a result on the other 40 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | DeepSeek V4 Flash 0423 | Mercury 2 | Leader |
|---|---|---|---|
| GPQA Diamond (Artificial Analysis run) | Not measured | 77.0% | Only Mercury 2 measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 17.1% | Only Mercury 2 measured |
| SimpleBench | 46.3% | Not measured | Only DeepSeek V4 Flash 0423 measured |
| LMArena Text: hard prompts | 1444 | 1362 | DeepSeek V4 Flash 0423 |
| LMArena Text: expert | 1441 | 1358 | DeepSeek V4 Flash 0423 |
| LMArena Text: hard prompts in English | 1449 | 1374 | DeepSeek V4 Flash 0423 |
| Kagi LLM Benchmark | 52.2% | Not measured | Only DeepSeek V4 Flash 0423 measured |
| Neither model has a result on the other 16 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index3 boards, none shared
| Benchmark | DeepSeek V4 Flash 0423 | Mercury 2 | Leader |
|---|---|---|---|
| LMArena Text: math | 1426 | Not measured | Only DeepSeek V4 Flash 0423 measured |
| LMArena Text: mathematical work | 1432 | Not measured | Only DeepSeek V4 Flash 0423 measured |
| MathArena | 24.8% | Not measured | Only DeepSeek V4 Flash 0423 measured |
| Neither model has a result on the other 11 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | DeepSeek V4 Flash 0423 | Mercury 2 | Leader |
|---|---|---|---|
| LMArena Text: science | 1446 | 1343 | DeepSeek V4 Flash 0423 |
| LMArena Text: medicine and healthcare | 1448 | 1363 | DeepSeek V4 Flash 0423 |
| LMArena Text: legal and government | 1439 | Not measured | Only DeepSeek V4 Flash 0423 measured |
| LMArena Text: business and finance | 1425 | 1349 | DeepSeek V4 Flash 0423 |
| Neither model has a result on the other 16 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index80
| Benchmark | DeepSeek V4 Flash 0423 | Mercury 2 | Leader |
|---|---|---|---|
| Design Arena: websites | 1207 | 1035 | DeepSeek V4 Flash 0423 |
| Design Arena: UI components | 1162 | 996 | DeepSeek V4 Flash 0423 |
| Design Arena: game dev | 1196 | 983 | DeepSeek V4 Flash 0423 |
| Design Arena: data viz | 1127 | 1010 | DeepSeek V4 Flash 0423 |
| Design Arena: 3D | 1188 | 982 | DeepSeek V4 Flash 0423 |
| Design Arena: all code categories | 1205 | 1021 | DeepSeek V4 Flash 0423 |
| Design Arena: SVG | 1154 | 997 | DeepSeek V4 Flash 0423 |
| Design Arena: ASCII art | 1109 | 988 | DeepSeek V4 Flash 0423 |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index110
| Benchmark | DeepSeek V4 Flash 0423 | Mercury 2 | Leader |
|---|---|---|---|
| IFBench | Not measured | 69.8% | Only Mercury 2 measured |
| Long context reasoning (AA-LCR) | Not measured | 43.7% | Only Mercury 2 measured |
| DTBench | 86.4% | Not measured | Only DeepSeek V4 Flash 0423 measured |
| LMCA | 35.9% | Not measured | Only DeepSeek V4 Flash 0423 measured |
| LMArena Text | 1432 | 1354 | DeepSeek V4 Flash 0423 |
| LMArena Text: instruction following | 1421 | 1328 | DeepSeek V4 Flash 0423 |
| LMArena Text: creative writing | 1403 | 1286 | DeepSeek V4 Flash 0423 |
| LMArena Text: English | 1441 | 1378 | DeepSeek V4 Flash 0423 |
| LMArena Text: non-English | 1419 | 1330 | DeepSeek V4 Flash 0423 |
| LMArena Text: Chinese | 1463 | 1414 | DeepSeek V4 Flash 0423 |
| LMArena Text: German | 1419 | Not measured | Only DeepSeek V4 Flash 0423 measured |
| LMArena Text: Japanese | 1389 | Not measured | Only DeepSeek V4 Flash 0423 measured |
| LMArena Text: Korean | 1383 | Not measured | Only DeepSeek V4 Flash 0423 measured |
| LMArena Text: French | 1439 | Not measured | Only DeepSeek V4 Flash 0423 measured |
| LMArena Text: Spanish | 1436 | Not measured | Only DeepSeek V4 Flash 0423 measured |
| LMArena Text: Russian | 1427 | 1304 | DeepSeek V4 Flash 0423 |
| LMArena Text: Polish | 1436 | Not measured | Only DeepSeek V4 Flash 0423 measured |
| LMArena Text: multi-turn | 1449 | 1357 | DeepSeek V4 Flash 0423 |
| LMArena Text: longer queries | 1434 | 1329 | DeepSeek V4 Flash 0423 |
| LMArena Text: writing and language | 1410 | 1300 | DeepSeek V4 Flash 0423 |
| LMArena Text: entertainment and media | 1400 | 1314 | DeepSeek V4 Flash 0423 |
| Neither model has a result on the other 27 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | DeepSeek V4 Flash 0423 | Mercury 2 | 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 0423 costs less
Repository review
50K input + 3K output tokens
DeepSeek V4 Flash 0423 costs less
Agent loop
200K input + 10K output tokens
DeepSeek V4 Flash 0423 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 | DeepSeek V4 Flash 0423 | Inception Mercury 2 |
|---|---|---|
| Maker | DeepSeek | Inception |
| Weights | Open weights | No public weights listed |
| Released | April 24, 2026 | March 4, 2026 |
| Context window | 1.05M | 128K |
| Input $/Mtok | $0.13 | $0.25 |
| Output $/Mtok | $0.28 | $0.75 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 1 | 1 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is DeepSeek V4 Flash 0423 better than Mercury 2 for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick DeepSeek V4 Flash 0423 for output tokens 2.7x cheaper ($0.28 vs $0.75 per million) and a larger context window (1.05M against 128K tokens).
Which is cheaper, DeepSeek V4 Flash 0423 or Mercury 2?
DeepSeek V4 Flash 0423 costs $0.13 per million input tokens and $0.28 per million output tokens; Mercury 2 costs $0.25 and $0.75. Cost per solved task is known for neither of them.
Which has the bigger context window, DeepSeek V4 Flash 0423 or Mercury 2?
DeepSeek V4 Flash 0423, with 1.05M tokens against 128K.
How many benchmarks is the DeepSeek V4 Flash 0423 vs Mercury 2 comparison based on?
35 benchmarks have a result for both models as of October 22, 2026. DeepSeek V4 Flash 0423's coding index rests on 1 independent benchmark and Mercury 2's on 1. Where only one model has a result, the page says so instead of naming a winner.