Mercury 3 vs Mistral Small 4
Mercury 3 costs 1.7x less per output token than Mistral Small 4 ($0.35 vs $0.60 per million). Updated October 21, 2026; no benchmark has tested both models yet.
- Coding
- No data
- Overall
- No data
- Output $/M
- $0.35
- Coding
- No data
- Overall
- No data
- Output $/M
- $0.60
Mercury 3 or Mistral Small 4: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick Mercury 3 for output tokens 1.7x cheaper ($0.35 vs $0.60 per million) and a larger context window (1M against 262K tokens).
No benchmark has tested both yet. Mercury 3 has results on Design Arena: websites, Design Arena: UI components and Design Arena: game dev; Mistral Small 4 on AA Coding Index, Vibe Code Bench (Vals AI) and SciCode. Compare them on price and context instead.
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
No call
Only Mistral Small 4 has a AA Intelligence Index result, 11.3.
Directional only
Agentic work
AA Agentic Index
No call
Only Mistral Small 4 has a AA Agentic Index result, 0.8.
Directional only
Web design
Design Arena: websites
No call
Only Mercury 3 has a Design Arena: websites result, 1244.
Directional only
Long documents
Listed context window
Mercury 3
Mercury 3 takes 1M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Mercury 3
Mercury 3 $0.0003, Mistral Small 4 $0.0004 per turn.
List prices
At a glance
- Coding index
- Mercury 3 not benchmarked, Mistral Small 4 not benchmarked.
- Widest category
- None yet: no category has been tested on both models.
- Widest single gap
- None yet: no benchmark has tested both models.
- Output price
- Mercury 3 $0.35 against Mistral Small 4 $0.60 per million output tokens, 1.7x apart.
- Context window
- Mercury 3 takes 1M tokens, Mistral Small 4 262K.
Benchmark by benchmark
Every board either model has a result on, a category to a fold; bars are each result on a 0 to 100 scale. Only one model is measured on each, so no row names a leader.
CodingDirectional onlySix of these boards feed the Vibe Coding Index5 boards measured
| Benchmark | Mercury 3 | Mistral Small 4 | Leader |
|---|---|---|---|
| AA Coding Index | Not measured | 26.6 | Only Mistral Small 4 measured |
| Vibe Code Bench (Vals AI) | Not measured | 0.0% | Only Mistral Small 4 measured |
| SciCode | Not measured | 38.8% | Only Mistral Small 4 measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 17.4% | Only Mistral Small 4 measured |
| ALE-Bench | Not measured | 497.6 | Only Mistral Small 4 measured |
| Neither model has a result on the other 34 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board measured
| Benchmark | Mercury 3 | Mistral Small 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 11.3 | Only Mistral Small 4 measured |
| Neither model has a result on the other 1 board here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index2 boards measured
| Benchmark | Mercury 3 | Mistral Small 4 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 0.8 | Only Mistral Small 4 measured |
| τ²-Bench Telecom | Not measured | 41.2% | Only Mistral Small 4 measured |
| Neither model has a result on the other 39 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index3 boards measured
| Benchmark | Mercury 3 | Mistral Small 4 | Leader |
|---|---|---|---|
| GPQA Diamond (Artificial Analysis run) | Not measured | 76.9% | Only Mistral Small 4 measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 9.9% | Only Mistral Small 4 measured |
| Kagi LLM Benchmark | Not measured | 40.5% | Only Mistral Small 4 measured |
| Neither model has a result on the other 19 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index5 boards measured
| Benchmark | Mercury 3 | Mistral Small 4 | Leader |
|---|---|---|---|
| Design Arena: websites | 1244 | Not measured | Only Mercury 3 measured |
| Design Arena: UI components | 1270 | Not measured | Only Mercury 3 measured |
| Design Arena: game dev | 1227 | Not measured | Only Mercury 3 measured |
| Design Arena: data viz | 1207 | Not measured | Only Mercury 3 measured |
| Design Arena: all code categories | 1240 | Not measured | Only Mercury 3 measured |
| Neither model has a result on the other 4 boards here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index4 boards measured
| Benchmark | Mercury 3 | Mistral Small 4 | Leader |
|---|---|---|---|
| IFBench | Not measured | 48.2% | Only Mistral Small 4 measured |
| Long context reasoning (AA-LCR) | Not measured | 49.7% | Only Mistral Small 4 measured |
| DTBench | Not measured | 70.9% | Only Mistral Small 4 measured |
| LMCA | Not measured | 20.6% | Only Mistral Small 4 measured |
| Neither model has a result on the other 42 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
Mercury 3 costs less
Repository review
50K input + 3K output tokens
Mercury 3 costs less
Agent loop
200K input + 10K output tokens
Mercury 3 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 | Inception Mercury 3 | Mistral Small 4 |
|---|---|---|
| Maker | Inception | Mistral AI |
| Weights | No public weights listed | Open weights |
| Released | October 16, 2026 | March 16, 2026 |
| Context window | 1M | 262K |
| Input $/Mtok | $0.10 | $0.15 |
| Output $/Mtok | $0.35 | $0.60 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 1 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Mercury 3 better than Mistral Small 4 for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick Mercury 3 for output tokens 1.7x cheaper ($0.35 vs $0.60 per million) and a larger context window (1M against 262K tokens).
Which is cheaper, Mercury 3 or Mistral Small 4?
Mercury 3 costs $0.10 per million input tokens and $0.35 per million output tokens; Mistral Small 4 costs $0.15 and $0.60. Cost per solved task is known for neither of them.
Which has the bigger context window, Mercury 3 or Mistral Small 4?
Mercury 3, with 1M tokens against 262K.
Has any benchmark tested both Mercury 3 and Mistral Small 4?
No benchmark has tested both yet. Mercury 3 has results on Design Arena: websites, Design Arena: UI components and Design Arena: game dev; Mistral Small 4 on AA Coding Index, Vibe Code Bench (Vals AI) and SciCode. Compare them on price and context instead. Data as of October 21, 2026.