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text model comparison

GPT-6 Luna vs Inkling 2 Small

GPT-6 Luna and Inkling 2 Small are both current text models, from OpenAI and Thinking Machines Lab. GPT-6 Luna is 67% cheaper per 1M input tokens than Inkling 2 Small, $0.10 vs $0.30. In Thinking Machines Lab's Inkling 2 Small model card, GPT-6 Luna scores 66.6% on DeepSWE v1.1 and Inkling 2 Small 72.1%. GPT-6 Luna has the larger context window, 1,050,000 vs 262,144 tokens.

Lower price per 1M input tokens
GPT-6 Luna$0.10 against $0.30
Longer context window
GPT-6 Luna1.05M tokens against 262K tokens
Newer release
Inkling 2 SmallNov 2026 against Sep 2026

Data verified November 6, 2026 · Dataset 2026-11-06

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Side by side

GPT-6 Luna and Inkling 2 Small, line by line

Prices in effect today, compared at the same tier wherever both list one. The better value in each row is highlighted.

FactGPT-6 LunaInkling 2 Small
Price
Price per 1M input tokens$0.10 (better)$0.30
Price per 1M output tokens$0.50 (better)$1
Independent benchmarks
Arena Text1441 Elo (#38 of 52)Not measured
Arena WebDev1579 Elo (#29 of 46)Not measured
GPQA Diamond90.5% (#26 of 41)Not measured
FrontierMath Tiers 1-3 (v2)78.9% (#17 of 41)Not measured
SimpleQA Verified41.4% (#28 of 38)Not measured
Specs
ProviderOpenAIThinking Machines Lab
Release dateSeptember 22, 2026November 5, 2026
AccessAPI onlyAPI only
Context window1,050,000 tokens262,144 tokens
Max output128,000 tokensNot reported
Inputtext, imagetext, image
Outputtexttext

No independent benchmark has scored both models yet. Each rank counts the current models scored on that benchmark.

Scores:Arena · 2026-11-03Epoch AI · 2026-11-03

Provider results

What the labs report

Results tables a lab published with one of its models, where it lists both GPT-6 Luna and Inkling 2 Small. These are the lab's own figures, not independent measurements, and each table is read on its own: labs run benchmarks with different harnesses and budgets.

Thinking Machines Lab, Inkling 2 Small model card, November 5, 2026Thinking Machines Lab · 2026-11-06

BenchmarkGPT-6 LunaInkling 2 Small
DeepSWE v1.166.6%72.1% (better)
Vibe Code Bench v1.181.7% (better)81.6%
SWE-Marathon v1.128.1%38.8% (better)
SWE-bench Multilingual78.2%81.2% (better)
SWE-bench Multimodal v237.5%43.1% (better)
SWE-bench Verified76.1%82.2% (better)
BioMysteryBench61.5%70.0% (better)
MCP Atlaspublic set77.8%85.0% (better)
Finance Agent v2.156.8%67.5% (better)
Excel Modeling Benchmark v1.170.0% (better)69.5%
Tax Agent Bench58.9%65.8% (better)
APEX-Accounting v1.1pass@110.8%14.5% (better)
APEX-Accounting v1.1mean score53.9%62.0% (better)
Diligence Benchbest harness42.1%58.1% (better)
Harvey LAB v1.14.2%21.7% (better)
Legal Research Bench30.3%46.6% (better)
PerceptionBench56.2%64.7% (better)
ScreenSpot-Pro81.1%83.8% (better)
ScreenSpot-Prowith Python87.6%91.5% (better)
CharXiv (RQ)81.8%85.6% (better)
CharXiv (RQ)with Python85.3%87.7% (better)
Chartography32.0%36.7% (better)
SAGE v1.183.4%88.6% (better)
LongBench v265.0%70.6% (better)
ComplexConstraints v1.027.3%44.5% (better)
CyberBench v1.176.3% (better)72.7%

Thinking Machines' table from the Inkling 2 Small model card, run at effort 0.99 (xhigh) with a 1M-token trajectory limit; where a benchmark's owner publishes scores (Datacurve, Scale AI, Surge, Mercor, Thoughtful, Vals), Thinking Machines uses them. DeepSeek-V4.1-Flash is the 1017 build. Left out here: the Artificial Analysis and Vals indexes, the rows Artificial Analysis ran (FrontierCode, Terminal-Bench, GDP.pdf, MMMU-Pro, HLE, CritPt, AA-LCR, AA-Omniscience, AutomationBench, EnterpriseOps-Gym, Tau 3 Banking), Arena and DesignArena ratings, PMPP-Hard (not a percentage), the safety rows, and JobBench, DAYJOB and Humanity's Sixth Sense, which we could not confirm are public.

Charts

Against every current text model

Where GPT-6 Luna and Inkling 2 Small land among the current models of their task, on every independent benchmark, on price and on context.

Where each stands

Only GPT-6 Luna has a current Arena Text score: #38 of 52. Each bar is the share of current models it beats.

GPT-6 Luna and Inkling 2 Small among the current text models, one row per benchmark, price and context window.

Independent benchmarks

Arena Text

GPT-6 Luna:#38of 52

1,441 Elo · ahead of 25%

Inkling 2 Small: Not scored

Arena WebDev

GPT-6 Luna:#29of 46

1,579 Elo · ahead of 38%

Inkling 2 Small: Not scored

GPQA Diamond

GPT-6 Luna:#26of 41

90.5% · ahead of 35%

Inkling 2 Small: Not scored

FrontierMath Tiers 1-3 (v2)

GPT-6 Luna:#17of 41

78.9% · ahead of 60%

Inkling 2 Small: Not scored

SimpleQA Verified

GPT-6 Luna:#28of 38

41.4% · ahead of 27%

Inkling 2 Small: Not scored

Price and context

Price per 1M input tokens

GPT-6 Luna:#1of 58

$0.10 · cheaper than 96%

Inkling 2 Small:#11of 58

$0.30 · cheaper than 75%

Price per 1M output tokens

GPT-6 Luna:#3of 58

$0.50 · cheaper than 93%

Inkling 2 Small:#10of 58

$1 · cheaper than 84%

Context window

GPT-6 Luna:#1of 67

1.05M tokens · longer than 85%

Inkling 2 Small:#57of 67

262K tokens · longer than 12%

Quality against price

Arena Text · measured October 28, 2026

GPT-6 Luna scores 1,441 at $0.2 (blended price per 1M tokens). The line joins the current models no other beats on both price and Arena Text score; hover any point to name it.

Quality against priceArena Text score against price for 44 text models, GPT-6 Luna and Inkling 2 Small marked.1,2501,3001,3501,4001,4501,5001,550$0.30$1$3$10MOST ATTRACTIVE QUADRANTMedian price $3Median 1,476Blended price per 1M tokens (3 input : 1 output), log scaleArena Text (Elo)GPT-6 Luna
Quality against price: the data
Arena Text score against price for 44 text models, GPT-6 Luna and Inkling 2 Small marked.
ModelProviderBlended price per 1M tokensArena Text (Elo)
Gemini 4 CarbonGoogle$41,528
Gemini 4 ArgonGoogle$41,520
Claude Opus 5.5Anthropic$81,509
Muse WonderMeta$81,507
Claude Fable 5Anthropic$201,504
Claude Fable 5.1Anthropic$201,504
Gemini 3.8 FlashGoogle$1.501,496
Muse Spark 1.3Meta$21,495
Claude Opus 5Anthropic$101,492
Kimi K3Moonshot Kimi$61,488
GPT-5.6 SolOpenAI$81,485
Gemini 3.6 FlashGoogle$31,483
GPT-5.5OpenAI$111,482
Claude Opus 4.8Anthropic$101,482
Qwen3.8-MaxAlibaba Qwen$31,482
GPT-6.1 SolOpenAI$41,481
GLM-5.3Z.ai$2.151,481
MiMo-V2.6-ProXiaomi MiMo$0.541,480
Claude Sonnet 5.5Anthropic$41,477
GLM-5.3-FlashZ.ai$0.241,477
GPT-6 AstraOpenAI$201,476
DeepSeek-V4.1-FlashDeepSeek$0.521,476
GPT-5.4OpenAI$5.631,475
Gemini 3 Flash PreviewGoogle$1.131,473
Grok 4.20xAI$1.561,472
GPT-5.6 TerraOpenAI$4.501,467
Grok 4.5xAI$31,465
DeepSeek-V4-ProDeepSeek$1.981,465
Claude Sonnet 5Anthropic$41,462
GPT-6 SolOpenAI$41,458
Gemini 3.5 Flash-LiteGoogle$0.851,456
Grok 4.6xAI$31,455
GPT-5.6 LunaOpenAI$0.451,453
MiMo-V2.6-FlashXiaomi MiMo$0.181,448
Step 5 PreviewStepFun$1.431,448
Grok 4.3xAI$1.561,442
GPT-6 LunaOpenAI$0.201,441
Grok 4.7xAI$31,441
Mistral Large 4Mistral AI$1.051,432
Claude Haiku 5.5Anthropic$0.201,425
GPT-4.1OpenAI$3.501,415
Solar Pro 4Upstage$0.521,388
GPT-4.1 miniOpenAI$0.701,383
GPT-4.1 nanoOpenAI$0.181,322

Cost

What each costs

Example workloads at each provider's listed rates, then every other rate either one lists. The cheaper figure in each row is highlighted.

The same work, priced

For 10M input and 2M output tokens, Inkling 2 Small costs 2.5 times as much as GPT-6 Luna, at each provider's listed rates.

What GPT-6 Luna and Inkling 2 Small cost for the same work, at the rates each provider lists.
  • 10M input and 2M output tokens

    Inkling 2 Small costs 2.5× as much

    GPT-6 Luna
    $2
    Inkling 2 Small
    $5
  • The same, with 9M of the input tokens cached

    Inkling 2 Small costs 2.2× as much

    GPT-6 Luna
    $1.19
    Inkling 2 Small
    $2.57
Workload or rateGPT-6 LunaInkling 2 Small
Example workloads
10M input and 2M output tokens$2 (better)$5
The same, with 9M of the input tokens cached$1.19 (better)$2.57
Other listed rates
1M input tokens, cached$0.01 (better)$0.03
1M input tokens, prompts over 272K tokens$0.20Not listed
1M output tokens, prompts over 272K tokens$0.75Not listed

Your own bill will differ. These figures use list prices and example workloads. The AI Model Cost Audit reviews your real usage, shortlists models that score as well for each task for less, and estimates the savings.

Launch price $100, regular price $150

Book the cost audit

Verdict

When to choose each

GPT-6 Luna

Where it leads

  • Lower input and output prices, $0.10 and $0.50 vs $0.30 and $1 per 1M tokens
  • Larger context window 1,050,000 vs 262,144 tokens
  • Cheaper cached input, $0.01 vs $0.03 per 1M tokens

Best for

  • High-volume summarisation, extraction and routing
  • Long-context budget work, where the 272k threshold is more forgiving than Haiku 5.5's 100k

Watch out for

  • Prompts over 272,000 tokens are rebilled at $0.20 input and $0.75 output for the whole request
  • A twentieth of GPT-6 Sol's price reflects a capability gap, not a discount on the same model

Inkling 2 Small

Where it leads

No measured lead over GPT-6 Luna in this data.

Best for

  • Agentic coding and office, finance and legal work at a low per-token price
  • Teams that want to post-train their own variant on Tinker

Watch out for

  • Closed weights for now: Thinking Machines says it will publish the full weights under Apache 2.0 the week after launch, once external safety testing ends; until then Tinker is the only way to use it
  • Tinker serves it with a 64K or 256K context, although the model card lists up to 1M tokens
  • In its lab's own table DeepSeek-V4.1-Flash scores higher on DeepSWE v1.1 (77.0% against 72.1%) and Claude Haiku 5.5 on Vibe Code Bench (90.4% against 81.6%); Thinking Machines also says it is less tuned for chat, and no independent benchmark score is recorded here yet

From benchmark to production

Building on GPT-6 Luna or Inkling 2 Small?

Public scores rarely hold on your own data. We test both models on your real tasks, then build the agent or pipeline around the one that wins.

AI Model Cost AuditLaunch price $100, regular price $150What the audit includes

FAQ

GPT-6 Luna vs Inkling 2 Small FAQ

Which is cheaper, GPT-6 Luna or Inkling 2 Small?

GPT-6 Luna is 67% cheaper per 1M input tokens than Inkling 2 Small, $0.10 vs $0.30. For 10M input and 2M output tokens, GPT-6 Luna costs $2 and Inkling 2 Small $5 at standard rates.

Which is cheaper with prompt caching, GPT-6 Luna or Inkling 2 Small?

GPT-6 Luna charges $0.01 per 1M cached input tokens, 90% below its standard input rate, and Inkling 2 Small $0.03, 90% below. With 9M of 10M input tokens cached and 2M output tokens, GPT-6 Luna costs $1.19 and Inkling 2 Small $2.57.

How do GPT-6 Luna and Inkling 2 Small compare in Thinking Machines Lab's own results?

In the Inkling 2 Small model card (November 5, 2026), Inkling 2 Small leads on DeepSWE v1.1, 72.1% to 66.6%; GPT-6 Luna leads on Vibe Code Bench v1.1, 81.7% to 81.6%; Inkling 2 Small leads on SWE-Marathon v1.1, 38.8% to 28.1%. These are Thinking Machines Lab's figures, not independent measurements.

Which has the larger context window, GPT-6 Luna or Inkling 2 Small?

GPT-6 Luna has the larger context window, 1,050,000 vs 262,144 tokens.

Production evaluation

Choosing between GPT-6 Luna and Inkling 2 Small?

Public benchmarks narrow the shortlist. We run both on your own tasks, data and cost limits, then build the routing and review controls to run the winner in production.

  • A head-to-head evaluation on your real workload
  • Routing between models by cost and difficulty