Model comparison

GPT-5.1 vs Inkling-Small

GPT-5.1 is the stronger model overall, scoring 48.8 to 46.5 on the Noometry Index. Inkling-Small costs 5.4× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Last verified . 29 shared benchmarks.

GPT-5.1 OpenAI

48.8

Rank #47 Confirmed

Inkling-Small Thinking Machines Lab

46.5

Rank #57 Confirmed

Summary

  • They share 29 benchmarks with published results for both. GPT-5.1 scores higher in 9 categories and Inkling-Small in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in instruction following, where GPT-5.1 leads 84.0 to 73.9.
  • The biggest single-benchmark swing is SimpleQA Verified: 48% for GPT-5.1 and 19.1% for Inkling-Small.
  • Inkling-Small is cheaper at $0.45 / $1.20 per million input/output tokens, against $1.25 / $10 for GPT-5.1.
  • Inkling-Small accepts more context: 524K tokens versus 400K.
  • Inkling-Small has downloadable open weights; the other is API-only.

Side by side

GPT-5.1 and Inkling-Small specifications
GPT-5.1Inkling-Small
ProviderOpenAIThinking Machines Lab
Noometry Index48.846.5
Released2025-11-132026-07-15
WeightsProprietaryOpen
Context window400K524K
Max output128K1.05M
Input $ / M tokens$1.25$0.45
Output $ / M tokens$10$1.20
Results tracked6333

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Category by category

Coding GPT-5.1 leads

GPT-5.1: 46.9 (#59), Inkling-Small: 43.3 (#80)

Coding benchmarks
BenchmarkGPT-5.1Inkling-Small
LMArena WebDev13951408
SciCode43.3%48.7%
LMArena Coding14541451
SWE-bench Verified68%—
SWE-bench Verified (bash only)66%—
GSO13.7%—
WeirdML60.8%—
LiveBench Coding72.5%—
ALE-Bench1,192—

Agentic & Tool Use Not comparable

GPT-5.1: 32.5 (#55), Inkling-Small: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1Inkling-Small
Terminal-Bench47.6%—
DeepResearch Bench42.8%—
LMArena Search1199—
Vending-Bench 21,473—

Reasoning Too close to call

GPT-5.1: 39.9 (#50), Inkling-Small: 39.0 (#53)

Reasoning benchmarks
BenchmarkGPT-5.1Inkling-Small
ARC-AGI-217.6%40.1%
ARC-AGI-172.8%84%
CritPt4.9%8.3%
Chess Puzzles32%18%
LMArena Hard Prompts14571424
Mystery Game Puzzles19%6%
Epoch Capabilities Index149.66150.13
SimpleBench53.2%—
EnigmaEval11.2%—
LiveBench Reasoning95.8%—
DTBench90.1%—
LiveBench Data Analysis72.1%—
LMCA43.9%—
ForecastBench58.1—
LiveBench78.8%—

Math GPT-5.1 leads

GPT-5.1: 50.3 (#45), Inkling-Small: 44.9 (#65)

Math benchmarks
BenchmarkGPT-5.1Inkling-Small
OTIS Mock AIME 2024-202588.6%90%
LMArena Math14461453
FrontierMath (Tiers 1-3)—46.3%
FrontierMath Tier 4—17.1%
ProofBench—6%
Omni-MATH46.4%—
LiveBench Math94.5%—
FrontierMath (Feb 2025 set)31%—
FrontierMath Tier 4 (v1)12.5%—

Knowledge GPT-5.1 leads

GPT-5.1: 50.5 (#65), Inkling-Small: 48.3 (#71)

Knowledge benchmarks
BenchmarkGPT-5.1Inkling-Small
GPQA Diamond87.6%88.5%
SimpleQA Verified48%19.1%
LMArena Expert14701442
Humanity's Last Exam23.7%—
MMLU-Pro57.9%—
Vectara Hallucination Rate10.9%—
GPQA (HELM)44.2%—

Multimodal GPT-5.1 leads

GPT-5.1: 44.0 (#17), Inkling-Small: 38.4 (#59)

Multimodal benchmarks
BenchmarkGPT-5.1Inkling-Small
LMArena Vision12501235
VPCT58.7%—
LMArena Document1403—

Multilingual GPT-5.1 leads

GPT-5.1: 54.0 (#51), Inkling-Small: 51.7 (#102)

Multilingual benchmarks
BenchmarkGPT-5.1Inkling-Small
LMArena Non-English14311400
LMArena Chinese14951458
LMArena French14511438
LMArena German14391412
LMArena Japanese14531399
LMArena Korean14011355
LMArena Russian14351392
LMArena Spanish14301426

Instruction Following GPT-5.1 leads

GPT-5.1: 84.0 (#1), Inkling-Small: 73.9 (#112)

Instruction Following benchmarks
BenchmarkGPT-5.1Inkling-Small
LMArena Instruction Following14421397
LiveBench Instruction Following93.3%—
IFEval93.5%—

Long Context GPT-5.1 leads

GPT-5.1: 47.6 (#14), Inkling-Small: 42.7 (#113)

Long Context benchmarks
BenchmarkGPT-5.1Inkling-Small
LMArena Longer Query14481401
CL-bench23.7%—
CL-bench Life17.3%—

Writing & Preference GPT-5.1 leads

GPT-5.1: 64.7 (#53), Inkling-Small: 59.8 (#102)

Writing & Preference benchmarks
BenchmarkGPT-5.1Inkling-Small
LMArena Text14431413
LMArena Creative Writing14271330
LMArena Multi-Turn14491420
EQ-Bench Creative Writing—1491
WildBench86.3%—
LiveBench Language80.2%—

Frequently asked questions

Is GPT-5.1 better than Inkling-Small?

GPT-5.1 is the stronger model overall, scoring 48.8 to 46.5 on the Noometry Index. Inkling-Small costs 5.4× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Which is cheaper, GPT-5.1 or Inkling-Small?

Inkling-Small is cheaper. It lists at $0.45 per million input tokens and $1.20 per million output tokens; GPT-5.1 lists at $1.25 and $10.

Is GPT-5.1 or Inkling-Small better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.9 versus 43.3 in the Noometry coding category.

Which has the bigger context window?

Inkling-Small does, with 524K tokens against 400K.

How many benchmarks do GPT-5.1 and Inkling-Small share?

29 benchmarks have published results for both models. GPT-5.1 has 63 scored results on Noometry and Inkling-Small has 33.

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