Model Comparison

Claude Haiku 4.5 vs GPT-5.6 LunaWhich is better in 2026?

GPT-5.6 Luna significantly outperforms across most benchmarks. Claude Haiku 4.5 is 1.1x cheaper per token.

Verdict: Claude Haiku 4.5 vs GPT-5.6 Luna — which is better?

Claude Haiku 4.5 (by Anthropic) and GPT-5.6 Luna (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Claude Haiku 4.5 outperforms in 0 benchmarks, while GPT-5.6 Luna is better at 2 benchmarks (GDPval-AA, GPQA). GPT-5.6 Luna significantly outperforms across most benchmarks.

On price, Claude Haiku 4.5 is roughly 1.1x 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.

Choose Claude Haiku 4.5 if…

  • cost matters — it's about 1.1x cheaper per token

Choose GPT-5.6 Luna if…

  • you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
  • you process long inputs — it offers a 1,050,000 token context window
  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Claude Haiku 4.5 outperforms in 0 benchmarks, while GPT-5.6 Luna is better at 2 benchmarks (GDPval-AA, GPQA).

GPT-5.6 Luna significantly outperforms across most benchmarks.

Tue Jul 21 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Claude Haiku 4.5 costs less

For input processing, Claude Haiku 4.5 ($1.00/1M tokens) costs the same as GPT-5.6 Luna ($1.00/1M tokens).

For output processing, Claude Haiku 4.5 ($5.00/1M tokens) is 1.2x cheaper than GPT-5.6 Luna ($6.00/1M tokens).

In conclusion, GPT-5.6 Luna is more expensive than Claude Haiku 4.5.*

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

Lowest available price from all providers
Tue Jul 21 2026 • llm-stats.com
Anthropic
Claude Haiku 4.5
Input tokens$1.00
Output tokens$5.00
Best providerAnthropic
OpenAI
GPT-5.6 Luna
Input tokens$1.00
Output tokens$6.00
Best providerOpenAI
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 Claude Haiku 4.5's 200,000 tokens. GPT-5.6 Luna can generate longer responses up to 128,000 tokens, while Claude Haiku 4.5 is limited to 64,000 tokens.

Anthropic
Claude Haiku 4.5
Input200,000 tokens
Output64,000 tokens
OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Tue Jul 21 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Haiku 4.5 and GPT-5.6 Luna support multimodal inputs.

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

Claude Haiku 4.5

Text
Images
Audio
Video

GPT-5.6 Luna

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Haiku 4.5

Proprietary

Closed source

GPT-5.6 Luna

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Haiku 4.5 was released on 2025-10-15, while GPT-5.6 Luna was released on 2026-07-09.

GPT-5.6 Luna is 9 months newer than Claude Haiku 4.5.

Claude Haiku 4.5

Oct 15, 2025

9 months ago

GPT-5.6 Luna

Jul 9, 2026

1 weeks ago

8mo newer

Knowledge Cutoff

When training data ends

Claude Haiku 4.5 has a knowledge cutoff of 2025-02-01, while GPT-5.6 Luna has a cutoff of 2026-02-16.

GPT-5.6 Luna has more recent training data (up to 2026-02-16), making it potentially better informed about events through that date compared to Claude Haiku 4.5 (2025-02-01).

Claude Haiku 4.5

Feb 2025

GPT-5.6 Luna

Feb 2026

1 yr newer

Provider Availability

Claude Haiku 4.5 is available from Anthropic, Vertex AI. GPT-5.6 Luna is available from OpenAI.

Claude Haiku 4.5

anthropic logo
Anthropic
Input Price:Input: $1.00/1MOutput Price:Output: $5.00/1M
vertex logo
Unknown Organization
Input Price:Input: $1.00/1MOutput Price:Output: $5.00/1M

GPT-5.6 Luna

openai logo
OpenAI
Input Price:Input: $1.00/1MOutput Price:Output: $6.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Less expensive output tokens
OpenAI
Larger context window (1,050,000 tokens)
Higher GDPval-AA score (53.1% vs 30.1%)
Higher GPQA score (92.3% vs 73.0%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude Haiku 4.5 and GPT-5.6 Luna side-by-side, then vote on the output you prefer.

Claude Haiku 4.5
✓ Preferred
GPT-5.6 Luna
Open in Playground
AI Model Comparison Table
Feature
Anthropic
Claude Haiku 4.5
OpenAI
GPT-5.6 Luna

FAQ

Common questions about Claude Haiku 4.5 vs GPT-5.6 Luna.

Which is better, Claude Haiku 4.5 or GPT-5.6 Luna?

GPT-5.6 Luna significantly outperforms across most benchmarks. Claude Haiku 4.5 is made by Anthropic and GPT-5.6 Luna is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Haiku 4.5 compare to GPT-5.6 Luna in benchmarks?

Claude Haiku 4.5 scores Tau2 Retail: 83.2%, MMMLU: 83.0%, Tau2 Telecom: 83.0%, AIME 2025: 80.7%, SWE-Bench Verified: 73.3%. 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%.

Is Claude Haiku 4.5 cheaper than GPT-5.6 Luna?

Both models cost $1.00 per million input tokens.

What are the context window sizes for Claude Haiku 4.5 and GPT-5.6 Luna?

Claude Haiku 4.5 supports 200K tokens and GPT-5.6 Luna supports 1.1M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Haiku 4.5 and GPT-5.6 Luna?

Key differences include context window (200K vs 1.1M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Haiku 4.5 and GPT-5.6 Luna?

Claude Haiku 4.5 is developed by Anthropic and GPT-5.6 Luna is developed by OpenAI.

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