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Comparison · 2 models · Updated Nov 2, 2026

GPT-6 Luna vs Claude Haiku 5.5

Too close to call on our weighted score (Claude Haiku 5.5 83, GPT-6 Luna 80). The right pick depends on what you value most.

  1. OpenAI

    GPT-6 Luna

    Released Sep 22, 2026New

    80/100
    • ECI156.8
    • Price$0.10 / $0.50
    • Context1.05M
    Full specs Remove GPT-6 Luna

  2. Anthropic

    Claude Haiku 5.5

    Released Oct 7, 2026New

    83/100
    • ECI160.4
    • Price$0.10 / $0.50
    • Context1M
    Full specs Remove Claude Haiku 5.5

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01 — Verdict

Too close to call

It is close. Our weighted score puts them within 2 points (Claude Haiku 5.5 83/100, GPT-6 Luna 80/100), so choose by what matters most for your work: Claude Haiku 5.5 for raw capability, GPT-6 Luna on price and GPT-6 Luna for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityClaude Haiku 5.5Capabilities Index (ECI): Claude Haiku 5.5 160.4 · GPT-6 Luna 156.8
  • Lowest priceSame priceGPT-6 Luna $0.20 · Claude Haiku 5.5 $0.20 per 1M tokens (3:1 blend)
  • Longest contextGPT-6 LunaGPT-6 Luna 1,050,000 · Claude Haiku 5.5 1,000,000 tokens
  • Widest inputsSame inputsGPT-6 Luna: Text, Images, PDFs · Claude Haiku 5.5: Text, Images, PDFs
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-6 LunaClaude Haiku 5.5
CapabilityCapabilities Index (ECI)50%8589
Price25%8080
Inputs & features15%8080
Context window10%6160
Overall100%80/10083/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

GPT-6 Luna vs Claude Haiku 5.5 specifications side by side
SpecificationGPT-6 LunaOpenAIClaude Haiku 5.5Anthropic
Capability
Capabilities Index (ECI)156.8160.4 (best)
ECI rank#28 of 165#14 of 165 (best)
GPQA DiamondGraduate-level science questions90.5% (best)89.7%
FrontierMath Tiers 1–3Research-level mathematics79.0% (best)75.1%
OTIS Mock AIME 2024–2025Competition mathematics98.9%98.9%
SimpleQA VerifiedShort factual questions41.4% (best)23.8%
Price per million tokens
Input$0.10$0.10
Output$0.50$0.50
Cached input$0.01$0.01
Blended (3:1)$0.20$0.20
Long-context rateOver 272K: $0.20 / $0.75Over 100K: $0.50 / $2.50
Price sourceOfficial OpenAI APIOfficial Anthropic API
Limits
Context window1,050,000 tokens (best)1,000,000 tokens
Max output128,000 tokens128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesYes
AudioNoNo
VideoNoNo
ReasoningYeslow · medium · high · xhigh · maxYeslow · medium · high · xhigh · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDgpt-6-lunaclaude-haiku-5-5
API providers35 (best)33
ReleasedSep 22, 2026Oct 7, 2026
Knowledge cutoffMay 18, 2026Jun 2026
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • GPT-6 Luna$2.00
  • Claude Haiku 5.5$2.00
04 — Questions

Which should you choose?

Which is better: GPT-6 Luna or Claude Haiku 5.5?

It is close. Our weighted score puts them within 2 points (Claude Haiku 5.5 83/100, GPT-6 Luna 80/100), so choose by what matters most for your work: Claude Haiku 5.5 for raw capability, GPT-6 Luna on price and GPT-6 Luna for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, GPT-6 Luna or Claude Haiku 5.5?

GPT-6 Luna and Claude Haiku 5.5 cost the same: $0.10 input / $0.50 output per million tokens.

Which scores higher on benchmarks?

Claude Haiku 5.5 scores higher on the Capabilities Index (ECI): Claude Haiku 5.5 160.4 (#14 of 165) and GPT-6 Luna 156.8 (#28 of 165). The confidence ranges of the top two overlap (157.3–163.8 vs 154.0–159.5), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-6 Luna 90.5%, Claude Haiku 5.5 89.7%; FrontierMath Tiers 1–3 — GPT-6 Luna 79.0%, Claude Haiku 5.5 75.1%; OTIS Mock AIME 2024–2025 — GPT-6 Luna 98.9%, Claude Haiku 5.5 98.9%; SimpleQA Verified — GPT-6 Luna 41.4%, Claude Haiku 5.5 23.8%.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-6 Luna and Claude Haiku 5.5 yet, so there is no like-for-like coding score. On overall capability, Claude Haiku 5.5 leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.

Which has the bigger context window?

GPT-6 Luna has the largest context window at 1,050,000 tokens, against 1,000,000 for Claude Haiku 5.5. Maximum output per response: GPT-6 Luna up to 128,000, Claude Haiku 5.5 up to 128,000 tokens.

Which can read images, PDFs, audio or video?

GPT-6 Luna accepts text, images and PDFs; Claude Haiku 5.5 accepts text, images and PDFs. They handle the same number of input types.

Are any of these open source?

No. GPT-6 Luna and Claude Haiku 5.5 are proprietary and only available through APIs and apps.

Which is newer?

Claude Haiku 5.5 is the newest, released Oct 7, 2026. GPT-6 Luna came out Sep 22, 2026. Knowledge cutoff: GPT-6 Luna May 18, 2026, Claude Haiku 5.5 Jun 2026.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.

05 — Keep comparing

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