Model comparison

Devstral Small 2505 vs Mistral Medium 3.5

Mistral Medium 3.5 is the stronger model overall, scoring 40.2 to 34.3 on the Noometry Index. Devstral Small 2505 costs 20× less per token, which makes it the better buy when Mistral Medium 3.5's lead doesn't matter for your workload.

Last verified October 10, 2026. 1 shared benchmarks.

Devstral Small 2505

Mistral AI

34.3

Rank #233 Reported

Mistral Medium 3.5

Mistral AI

40.2

Rank #152 Confirmed

Summary

They share 1 benchmark with published results for both. Devstral Small 2505 scores higher in 2 categories and Mistral Medium 3.5 in 0 categories; 2 gaps are clear of the uncertainty.
Devstral Small 2505 is cheaper at $0.10 / $0.30 per million input/output tokens, against $1.50 / $7.50 for Mistral Medium 3.5.
Mistral Medium 3.5 accepts more context: 262K tokens versus 128K.

Side by side

Devstral Small 2505 and Mistral Medium 3.5 specifications
	Devstral Small 2505	Mistral Medium 3.5
Provider	Mistral AI	Mistral AI
Noometry Index	34.3	40.2
Released	2025-05-07	—
Weights	Open	Open
Context window	128K	262K
Max output	128K	210K
Input $ / M tokens	$0.10	$1.50
Output $ / M tokens	$0.30	$7.50
Results tracked	4	22

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Category by category

Coding Devstral Small 2505 leads

Devstral Small 2505: 38.9 (#166), Mistral Medium 3.5: 36.0 (#213)

Coding benchmarks
Benchmark	Devstral Small 2505	Mistral Medium 3.5
SWE-bench Verified (bash only)	56.4%	—
LMArena WebDev	—	1264
SciCode	28.8%	—
LMArena Coding	—	1461

Reasoning Devstral Small 2505 leads

Devstral Small 2505: 19.7 (#252), Mistral Medium 3.5: 17.3 (#295)

Reasoning benchmarks
Benchmark	Devstral Small 2505	Mistral Medium 3.5
Kagi LLM Benchmark	37.7%	41.4%
NYT Connections (extended)	—	12.9%
CritPt	0%	—
LMArena Hard Prompts	—	1436
Epoch Capabilities Index	—	141.35

Math Not comparable

Devstral Small 2505: —, Mistral Medium 3.5: 39.1 (#113)

Math benchmarks
Benchmark	Devstral Small 2505	Mistral Medium 3.5
LMArena Math	—	1431

Knowledge Not comparable

Devstral Small 2505: —, Mistral Medium 3.5: 40.0 (#126)

Knowledge benchmarks
Benchmark	Devstral Small 2505	Mistral Medium 3.5
LMArena Expert	—	1432

Multimodal Not comparable

Devstral Small 2505: —, Mistral Medium 3.5: 38.3 (#65)

Multimodal benchmarks
Benchmark	Devstral Small 2505	Mistral Medium 3.5
LMArena Vision	—	1223

Multilingual Not comparable

Devstral Small 2505: —, Mistral Medium 3.5: 51.9 (#100)

Multilingual benchmarks
Benchmark	Devstral Small 2505	Mistral Medium 3.5
LMArena Non-English	—	1404
LMArena Chinese	—	1442
LMArena French	—	1448
LMArena German	—	1451
LMArena Korean	—	1385
LMArena Russian	—	1395
LMArena Spanish	—	1409

Instruction Following Not comparable

Devstral Small 2505: —, Mistral Medium 3.5: 74.6 (#90)

Instruction Following benchmarks
Benchmark	Devstral Small 2505	Mistral Medium 3.5
LMArena Instruction Following	—	1415

Long Context Not comparable

Devstral Small 2505: —, Mistral Medium 3.5: 43.2 (#103)

Long Context benchmarks
Benchmark	Devstral Small 2505	Mistral Medium 3.5
LMArena Longer Query	—	1415

Writing & Preference Not comparable

Devstral Small 2505: —, Mistral Medium 3.5: 58.5 (#117)

Writing & Preference benchmarks
Benchmark	Devstral Small 2505	Mistral Medium 3.5
LMArena Text	—	1421
LMArena Creative Writing	—	1374
EQ-Bench 4	—	993
LMArena Multi-Turn	—	1423

Frequently asked questions

Is Devstral Small 2505 better than Mistral Medium 3.5?

Which is cheaper, Devstral Small 2505 or Mistral Medium 3.5?

Devstral Small 2505 is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; Mistral Medium 3.5 lists at $1.50 and $7.50.

Is Devstral Small 2505 or Mistral Medium 3.5 better for coding?

Devstral Small 2505 scores higher on coding benchmarks: 38.9 versus 36.0 in the Noometry coding category.

Which has the bigger context window?

Mistral Medium 3.5 does, with 262K tokens against 128K.

How many benchmarks do Devstral Small 2505 and Mistral Medium 3.5 share?

1 benchmark has published results for both models. Devstral Small 2505 has 4 scored results on Noometry and Mistral Medium 3.5 has 22.