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Claude Haiku 5.5 vs GPT-6 Luna
Claude Haiku 5.5 scores higher than GPT-6 Luna on all 4 public leaderboards that rate both. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, Claude Haiku 5.5 is at 50.2 and GPT-6 Luna at 31.4 (out of 100).
Scores as published by each board; table composed October 8, 2026.
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Leaderboard by leaderboard
| Board | Claude Haiku 5.5 | GPT-6 Luna | Higher |
|---|---|---|---|
| LMArena Elo (community votes) | 1,586.9 | 1,580.9 | Claude Haiku 5.5 |
| LiveBench global average (0-100) | 72.1 | 72 | Claude Haiku 5.5 |
| Vals AI Vals Index accuracy % · weighted finance + coding tasks | 54.3 | 51.2 | Claude Haiku 5.5 |
| Artificial Analysis intelligence index · measured runs only | 43.4 | 38.1 | Claude Haiku 5.5 |
Raw scores are each board's own scale, so compare within a row, not across rows. Full table: the bench index.
For coding
On the ArtificialWatch coding index, Claude Haiku 5.5 is at 73.5 (#11 of 35) and GPT-6 Luna at 26.5 (#27). Claude Haiku 5.5 scores higher on all 2 coding boards that rate both.
| Coding board | Claude Haiku 5.5 | GPT-6 Luna |
|---|---|---|
| LiveBench · Coding | 67.5 | 65.1 |
| Vals Vibe Code Bench | 90.4 | 81.6 |
Claude Haiku 5.5 at a glance
- Developer
- Anthropic
- Status
- Live since October 7, 2026
- API price
- $0.10 input / $0.50 output per 1M tokens · Anthropic, claude-haiku-5-5
- Context window
- 1M tokens
Live — Oct 7 · $0.10/$0.50 per MTok for prompts up to 100K tokens, $0.50/$2.50 above · cache reads $0.01 / $0.05 · 1M ctx / 128K out · knowledge cutoff Jun 2026 · in the API, the Claude apps, AWS, Google Cloud and Microsoft Foundry the same day · Anthropic's own table: OSWorld 2.1 72.4% (GPT-6 Luna 48.9%, Haiku 4.5 15.7%), Terminal-Bench 4.0 39.2% (Luna 16.4%) · Artificial Analysis Intelligence Index 43 at max effort, #2 of 179 in its price tier (read Oct 7) · our sweep fired on claude-haiku-5-5 at 17:52 UTC, OpenRouter listed it at 18:31.
Claude Haiku 5.5 is out at $0.10 / $0.50, a tenth of Haiku 4.5's price
2026-10-07 · Anthropic released Claude Haiku 5.5 on October 7 as claude-haiku-5-5, on the Claude API, Amazon Bedrock, Google Cloud, Microsoft Foundry and in the Claude apps.
GPT-6 Luna at a glance
- Developer
- OpenAI
- Status
- Live since September 22, 2026
- API price
- $0.10 input / $0.50 output per 1M tokens · OpenAI, gpt-6-luna
- Context window
- 1.05M tokens
Live — Sep 22, in the API and ChatGPT (Free and Go too) the same day · the cheap, high-volume tier · models.dev lists gpt-6-luna on OpenAI's own API (read Sep 24).
OpenAI opens the Decisions API: GPT-6 Luna returns probabilities, choices and scores for $0.10 per million input tokens
2026-10-06 · OpenAI has opened a public beta of the Decisions API, a new endpoint (POST /v1/decisions) where the model answers a question about your input with a number or a label instead of writing text. GPT-6 Luna is the only model it runs.
Claude Haiku 5.5 vs GPT-6 Luna: quick answers
Which is better, Claude Haiku 5.5 or GPT-6 Luna?
It depends on what you measure. Claude Haiku 5.5 scores higher than GPT-6 Luna on all 4 public leaderboards that rate both. Claude Haiku 5.5's widest lead is on Artificial Analysis. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, Claude Haiku 5.5 is at 50.2 and GPT-6 Luna at 31.4 (out of 100).
Which is newer, Claude Haiku 5.5 or GPT-6 Luna?
Claude Haiku 5.5. It went live on October 7, 2026, 15 days after GPT-6 Luna (September 22, 2026).
Which is cheaper, Claude Haiku 5.5 or GPT-6 Luna?
They cost the same per token. On each vendor's own API, Claude Haiku 5.5 is $0.10 input / $0.50 output per million tokens and GPT-6 Luna is $0.10 input / $0.50 output per million tokens. Claude Haiku 5.5's rate rises for prompts over 100K tokens; GPT-6 Luna's rate rises for prompts over 272K tokens. Prices as published in the models.dev catalog, as of 2026-10-08.
Which has the bigger context window, Claude Haiku 5.5 or GPT-6 Luna?
GPT-6 Luna, at 1.05M tokens against Claude Haiku 5.5's 1M, as each vendor lists it.
How do Claude Haiku 5.5 and GPT-6 Luna compare for coding?
On the ArtificialWatch coding index, Claude Haiku 5.5 is at 73.5 (#11 of 35) and GPT-6 Luna at 26.5 (#27). Claude Haiku 5.5 scores higher on all 2 coding boards that rate both.
Who makes Claude Haiku 5.5 and GPT-6 Luna?
Claude Haiku 5.5 is from Anthropic; GPT-6 Luna is from OpenAI.
Where do these numbers come from?
Each score is the leaderboard's own published figure, read by ArtificialWatch (table composed October 8, 2026). Boards measure different things, so raw scores are only comparable within a row.
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Also: the bench index · API pricing · the wire