Model comparison

Devstral Small 2505 vs Grok 4.20 (Non-Reasoning)

Grok 4.20 (Non-Reasoning) is the stronger model overall, scoring 48.6 to 34.3 on the Noometry Index. Devstral Small 2505 costs 10× less per token, which makes it the better buy when Grok 4.20 (Non-Reasoning)'s lead doesn't matter for your workload.

Last verified . 1 shared benchmarks.

Devstral Small 2505 Mistral AI

34.3

Rank #233 Reported

Grok 4.20 (Non-Reasoning) xAI

48.6

Rank #54 Confirmed

Summary

  • They share 1 benchmark with published results for both. Devstral Small 2505 scores higher in 0 categories and Grok 4.20 (Non-Reasoning) in 2 categories; 2 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Grok 4.20 (Non-Reasoning) leads 52.3 to 19.7.
  • The biggest single-benchmark swing is Kagi LLM Benchmark: 37.7% for Devstral Small 2505 and 75% for Grok 4.20 (Non-Reasoning).
  • Devstral Small 2505 is cheaper at $0.10 / $0.30 per million input/output tokens, against $1.25 / $2.50 for Grok 4.20 (Non-Reasoning).
  • Grok 4.20 (Non-Reasoning) accepts more context: 1M tokens versus 128K.
  • Devstral Small 2505 has downloadable open weights; the other is API-only.

Side by side

Devstral Small 2505 and Grok 4.20 (Non-Reasoning) specifications
Devstral Small 2505Grok 4.20 (Non-Reasoning)
ProviderMistral AIxAI
Noometry Index34.348.6
Released2025-05-072026-02-17
WeightsOpenProprietary
Context window128K1M
Max output128K30K
Input $ / M tokens$0.10$1.25
Output $ / M tokens$0.30$2.50
Results tracked446

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Category by category

Coding Grok 4.20 (Non-Reasoning) leads

Devstral Small 2505: 38.9 (#166), Grok 4.20 (Non-Reasoning): 42.1 (#112)

Coding benchmarks
BenchmarkDevstral Small 2505Grok 4.20 (Non-Reasoning)
SWE-bench Verified (bash only)56.4%—
LMArena WebDev—1375
SciCode28.8%—
WeirdML—52.3%
LMArena Coding—1459
ALE-Bench—1,150

Agentic & Tool Use Not comparable

Devstral Small 2505: —, Grok 4.20 (Non-Reasoning): 34.4 (#46)

Agentic & Tool Use benchmarks
BenchmarkDevstral Small 2505Grok 4.20 (Non-Reasoning)
Terminal-Bench—57.3%
τ²-bench Banking—18%
LMArena Search—1189
Vending-Bench 2—4,663

Reasoning Grok 4.20 (Non-Reasoning) leads

Devstral Small 2505: 19.7 (#252), Grok 4.20 (Non-Reasoning): 52.3 (#32)

Reasoning benchmarks
BenchmarkDevstral Small 2505Grok 4.20 (Non-Reasoning)
Kagi LLM Benchmark37.7%75%
ARC-AGI-2—65.1%
NYT Connections (extended)—85.4%
ARC-AGI-1—89.5%
CritPt0%—
Chess Puzzles—24%
Thematic Generalization—63.8%
LMArena Hard Prompts—1451
DTBench—90.1%
LMCA—38.7%
Epoch Capabilities Index—151.98
ForecastBench—61.4

Math Not comparable

Devstral Small 2505: —, Grok 4.20 (Non-Reasoning): 48.2 (#65)

Math benchmarks
BenchmarkDevstral Small 2505Grok 4.20 (Non-Reasoning)
FrontierMath (Tiers 1-3)—44.9%
FrontierMath Tier 4—17.1%
OTIS Mock AIME 2024-2025—92.2%
ProofBench—14%
LMArena Math—1455

Knowledge Not comparable

Devstral Small 2505: —, Grok 4.20 (Non-Reasoning): 52.8 (#60)

Knowledge benchmarks
BenchmarkDevstral Small 2505Grok 4.20 (Non-Reasoning)
GPQA Diamond—89.3%
SimpleQA Verified—30.2%
LMArena Expert—1439

Multimodal Not comparable

Devstral Small 2505: —, Grok 4.20 (Non-Reasoning): 33.3 (#98)

Multimodal benchmarks
BenchmarkDevstral Small 2505Grok 4.20 (Non-Reasoning)
LMArena Vision—1263
Blueprint-Bench 2—0%
LMArena Document—1416

Multilingual Not comparable

Devstral Small 2505: —, Grok 4.20 (Non-Reasoning): 54.5 (#40)

Multilingual benchmarks
BenchmarkDevstral Small 2505Grok 4.20 (Non-Reasoning)
LMArena Non-English—1441
LMArena Chinese—1481
LMArena French—1476
LMArena German—1465
LMArena Japanese—1449
LMArena Korean—1417
LMArena Russian—1458
LMArena Spanish—1443

Instruction Following Not comparable

Devstral Small 2505: —, Grok 4.20 (Non-Reasoning): 74.8 (#83)

Instruction Following benchmarks
BenchmarkDevstral Small 2505Grok 4.20 (Non-Reasoning)
LMArena Instruction Following—1420

Long Context Not comparable

Devstral Small 2505: —, Grok 4.20 (Non-Reasoning): 45.5 (#34)

Long Context benchmarks
BenchmarkDevstral Small 2505Grok 4.20 (Non-Reasoning)
CL-bench—22.2%
CL-bench Life—11.9%
LMArena Longer Query—1437

Writing & Preference Not comparable

Devstral Small 2505: —, Grok 4.20 (Non-Reasoning): 65.7 (#44)

Writing & Preference benchmarks
BenchmarkDevstral Small 2505Grok 4.20 (Non-Reasoning)
LMArena Text—1451
LMArena Creative Writing—1438
EQ-Bench Creative Writing—1574
LMArena Multi-Turn—1456

Frequently asked questions

Is Devstral Small 2505 better than Grok 4.20 (Non-Reasoning)?

Grok 4.20 (Non-Reasoning) is the stronger model overall, scoring 48.6 to 34.3 on the Noometry Index. Devstral Small 2505 costs 10× less per token, which makes it the better buy when Grok 4.20 (Non-Reasoning)'s lead doesn't matter for your workload.

Which is cheaper, Devstral Small 2505 or Grok 4.20 (Non-Reasoning)?

Devstral Small 2505 is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; Grok 4.20 (Non-Reasoning) lists at $1.25 and $2.50.

Is Devstral Small 2505 or Grok 4.20 (Non-Reasoning) better for coding?

Grok 4.20 (Non-Reasoning) scores higher on coding benchmarks: 42.1 versus 38.9 in the Noometry coding category.

Which has the bigger context window?

Grok 4.20 (Non-Reasoning) does, with 1M tokens against 128K.

How many benchmarks do Devstral Small 2505 and Grok 4.20 (Non-Reasoning) share?

1 benchmark has published results for both models. Devstral Small 2505 has 4 scored results on Noometry and Grok 4.20 (Non-Reasoning) has 46.

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