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GPT-5.6 Luna vs Inkling-Small

GPT-5.6 Luna leads the LLM Stats Score 46.5 to 39.3. GPT-5.6 Luna is 1.2x cheaper per token.

OpenAI · Thinking Machines Lab · Updated for 2026

Which is better?

GPT-5.6 Luna leads the overall LLM Stats Score 46.5 to 39.3, ranking #21 overall.

In the 7 individual benchmarks reported for both models, GPT-5.6 Luna wins 6; this is a narrower head-to-head signal than the composite indexes.

On price, GPT-5.6 Luna is roughly 1.2x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5.6 Luna also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose GPT-5.6 Luna

  • overall performance matters — it scores 46.5 and ranks #21 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 6 of 7 exact shared results
  • cost matters — it's about 1.2x cheaper per token
  • you process long inputs — it offers a 1,050,000 token context window

Choose Inkling-Small

  • you want the most recent training data — it shipped Jul 2026
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Core performance indexes
46.5
#21
39.3
#53
45.6
#25
39.0
#52
39.9
#13
31.1
#45
33.7
#18
24.8
#45
Cost, coverage & limits
Benchmark wins
6 of 7
1 of 7
Input price
$0.20 / M
$0.30 / M
Output price
$1.20 / M
$1.20 / M
Context window
1,050,000
256,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

4 shared
Index
GPT-5.6 Luna
Inkling-Small
29.1#81
34.2#46
25.3#42
19.6#64
27.6#19
23.3#38
25.7#37
17.8#68
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

44 reported for GPT-5.6 Luna · 24 for Inkling-Small

7 shared

GPT-5.6 Luna outperforms in 6 benchmarks (Artificial Analysis, BrowseComp, GPQA, MMMU-Pro, SWE-Bench Pro, Terminal-Bench 2.1), while Inkling-Small is better at 1 benchmark (Toolathlon).

GPT-5.6 Luna significantly outperforms across most benchmarks.

Fri Aug 28 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GPT-5.6 Luna costs less

For input processing, GPT-5.6 Luna ($0.20/1M tokens) is 1.5x cheaper than Inkling-Small ($0.30/1M tokens).

For output processing, GPT-5.6 Luna ($1.20/1M tokens) costs the same as Inkling-Small ($1.20/1M tokens).

In conclusion, Inkling-Small is more expensive than GPT-5.6 Luna.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Fri Aug 28 2026 • llm-stats.com
OpenAI
GPT-5.6 Luna
Input tokens$0.20
Output tokens$1.20
Best providerOpenAI
Thinking Machines Lab
Inkling-Small
Input tokens$0.30
Output tokens$1.20
Best providerUnknown Organization
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

GPT-5.6 Luna accepts 1,050,000 input tokens compared to Inkling-Small's 256,000 tokens. Inkling-Small can generate longer responses up to 256,000 tokens, while GPT-5.6 Luna is limited to 128,000 tokens.

OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Thinking Machines Lab
Inkling-Small
Input256,000 tokens
Output256,000 tokens
Fri Aug 28 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both GPT-5.6 Luna and Inkling-Small support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

GPT-5.6 Luna

Text
Images
Audio
Video

Inkling-Small

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-5.6 Luna is licensed under a proprietary license, while Inkling-Small uses Apache 2.0.

License differences may affect how you can use these models in commercial or open-source projects.

GPT-5.6 Luna

Proprietary

Closed source

Inkling-Small

Apache 2.0

Open weights

Release Timeline

When each model was launched

GPT-5.6 Luna was released on 2026-07-09, while Inkling-Small was released on 2026-07-30.

Inkling-Small is 1 month newer than GPT-5.6 Luna.

GPT-5.6 Luna

Jul 9, 2026

1 months ago

Inkling-Small

Jul 30, 2026

4 weeks ago

3w newer

Knowledge Cutoff

When training data ends

GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while Inkling-Small's cutoff date is not specified.

We can confirm GPT-5.6 Luna's training data extends to 2026-02-16, but cannot make a direct comparison without Inkling-Small's cutoff date.

GPT-5.6 Luna

Feb 2026

Inkling-Small

Provider Availability

GPT-5.6 Luna is available from OpenAI. Inkling-Small is available from Thinking Machines Lab.

GPT-5.6 Luna

openai logo
OpenAI
Input Price:Input: $0.20/1MOutput Price:Output: $1.20/1M

Inkling-Small

thinking-machines logo
Unknown Organization
Input Price:Input: $0.30/1MOutput Price:Output: $1.20/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against GPT-5.6 Luna and Inkling-Small side-by-side, then vote on the output you prefer.

GPT-5.6 Luna
✓ Preferred
Inkling-Small
Open in Playground

FAQ

Common questions about GPT-5.6 Luna vs Inkling-Small.

Which is better, GPT-5.6 Luna or Inkling-Small?

GPT-5.6 Luna leads the LLM Stats Score 46.5 to 39.3. GPT-5.6 Luna is made by OpenAI and Inkling-Small is made by Thinking Machines Lab. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT-5.6 Luna compare to Inkling-Small in benchmarks?

GPT-5.6 Luna scores Connectors: 99.9%, HealthBench Consensus: 95.1%, GPQA: 92.3%, Search and Function-Calling: 89.7%, Capture-the-Flag Challenges (Internal): 85.2%. Inkling-Small scores AIME 2026: 95.5%, VoiceBench Avg: 90.1%, GPQA: 89.5%, Global-MMLU-Lite: 86.7%, ARC-AGI: 84.0%.

Is GPT-5.6 Luna cheaper than Inkling-Small?

GPT-5.6 Luna is 1.5x cheaper for input tokens. GPT-5.6 Luna costs $0.20/M input and $1.20/M output via openai. Inkling-Small costs $0.30/M input and $1.20/M output via thinking-machines.

What are the context window sizes for GPT-5.6 Luna and Inkling-Small?

GPT-5.6 Luna supports 1.1M tokens and Inkling-Small supports 256K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-5.6 Luna and Inkling-Small?

Key differences include LLM Stats Score (46.5 vs 39.3), context window (1.1M vs 256K), input pricing ($0.20 vs $0.30/M), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.6 Luna and Inkling-Small?

GPT-5.6 Luna is developed by OpenAI and Inkling-Small is developed by Thinking Machines Lab.