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Claude Haiku 5.5 vs Claude Opus 5.5
Claude Opus 5.5 scores higher than Claude Haiku 5.5 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 Claude Opus 5.5 at 100 (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 | Claude Opus 5.5 | Higher |
|---|---|---|---|
| LMArena Elo (community votes) | 1,586.9 | 1,813 | Claude Opus 5.5 |
| LiveBench global average (0-100) | 72.1 | 83.2 | Claude Opus 5.5 |
| Vals AI Vals Index accuracy % · weighted finance + coding tasks | 54.3 | 67 | Claude Opus 5.5 |
| Artificial Analysis intelligence index · measured runs only | 43.4 | 57.6 | Claude Opus 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 Claude Opus 5.5 at 96.9 (#1). Claude Haiku 5.5 scores higher on 1 of the 2 coding boards that rate both and Claude Opus 5.5 on 1.
| Coding board | Claude Haiku 5.5 | Claude Opus 5.5 |
|---|---|---|
| LiveBench · Coding | 67.5 | 80.5 |
| Vals Vibe Code Bench | 90.4 | 90.3 |
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.
Claude Opus 5.5 at a glance
- Developer
- Anthropic
- Status
- Live since September 22, 2026
- API price
- $4 input / $20 output per 1M tokens · Anthropic, claude-opus-5-5
- Context window
- 1M tokens
Live — Sep 22 · $4/$20 per MTok, down from Opus 5 at $5/$25 · 1M ctx / 128K out · adaptive thinking always on, default effort medium · cache reads 5% of base input · Anthropic now says start here for most workloads, and Opus 5 is legacy.
Claude Opus 5.5 ships at $4/$20 - and that is LESS than the Opus 5 it replaces
2026-09-22 · Claude Opus 5.5 is live. Our sweep read the id claude-opus-5-5 at 16:24:44 UTC on September 22 and the alert went out at 16:25:45 - 61 seconds later, to 307 inboxes and one phone. The hunt that caught it was armed the previous day, before the model had a confirmed name, on the version range rather than on the rumour.
Markets put the next Claude Opus at 83% by Thursday — the name going around is 5.5
2026-09-21 · Polymarket's "Next Claude Opus released by...?" book, read directly at 06:49 UTC, September 21: 83% by September 24, 91% by September 27, 95% by September 30. Polymarket's own post about nine hours earlier had Thursday at 72%, so the number has been climbing through the day.
Claude Haiku 5.5 vs Claude Opus 5.5: quick answers
Which is better, Claude Haiku 5.5 or Claude Opus 5.5?
It depends on what you measure. Claude Opus 5.5 scores higher than Claude Haiku 5.5 on all 4 public leaderboards that rate both. Claude Opus 5.5's widest lead is on LiveBench. 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 Claude Opus 5.5 at 100 (out of 100).
Which is newer, Claude Haiku 5.5 or Claude Opus 5.5?
Claude Haiku 5.5. It went live on October 7, 2026, 15 days after Claude Opus 5.5 (September 22, 2026).
Which is cheaper, Claude Haiku 5.5 or Claude Opus 5.5?
Claude Haiku 5.5 is cheaper on both input and output. On each vendor's own API, Claude Haiku 5.5 is $0.10 input / $0.50 output per million tokens and Claude Opus 5.5 is $4 input / $20 output per million tokens. Claude Haiku 5.5's rate rises for prompts over 100K 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 Claude Opus 5.5?
Neither. Both take 1M tokens.
How do Claude Haiku 5.5 and Claude Opus 5.5 compare for coding?
On the ArtificialWatch coding index, Claude Haiku 5.5 is at 73.5 (#11 of 35) and Claude Opus 5.5 at 96.9 (#1). Claude Haiku 5.5 scores higher on 1 of the 2 coding boards that rate both and Claude Opus 5.5 on 1.
Who makes Claude Haiku 5.5 and Claude Opus 5.5?
Both are from Anthropic.
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