Decision summary
- New Anthropic API traffic -> Claude Haiku 5.5
- Claude Code on the Anthropic API -> haiku alias is Haiku 5.5
- Bedrock, Google Cloud Agent Platform, or Foundry haiku alias -> confirm the resolved ID before you assume 5.5
- Pinned 4.5 quality bar -> replay before you delete the pin
Claude family comparison
Frontier comparisonClaude Haiku 5.5 vs Claude Haiku 4.5
Claude Haiku 5.5, released October 7, 2026, is the current Haiku.
Featured · Updated today · Last verified: October 2026
Choose Claude Haiku 5.5 when
New high-volume classification, routing, extraction, and subagent work.
Choose Claude Haiku 4.5 when
Pinned Haiku 4.5 calls that have not been replayed on 5.5.
- New Anthropic API traffic: Claude Haiku 5.5
- Claude Code on the Anthropic API: haiku alias is Haiku 5.5
- Bedrock, Google Cloud Agent Platform, or Foundry haiku alias: confirm the resolved ID before you assume 5.5
Decision axes: Best for · Access · Context · List price
Reasoning
Haiku 5.5 uses adaptive thinking with a medium default. Do not copy that onto 4.5.
Coding
Both are the fast Claude tier. 5.5 is the one Claude Code's Anthropic API alias selects.
Multimodal
Haiku 5.5 takes text and images and returns text.
Speed
Anthropic still calls Haiku the fast tier. 5.5 also changes the tokenizer.
Enterprise
Provider aliases differ. Bedrock, Google Cloud, and Foundry can still resolve haiku to 4.5.
Curated matrix for Claude Haiku 5.5 vs Claude Haiku 4.5 — confirm live limits and pricing on each vendor’s official pages.
How they compare
Criterion-by-criterion notes from the catalog—not a ranking. Validate on your own gold set.
| Criterion | Claude Haiku 5.5 | Claude Haiku 4.5 |
|---|---|---|
| Best for | New high-volume classification, routing, extraction, and subagent work. | Pinned Haiku 4.5 calls that have not been replayed on 5.5. |
| Access | API ID claude-haiku-5-5. Released October 7, 2026. Claude Code haiku alias on the Anthropic API, from v2.1.293. | Still listed under legacy models on claude.com/pricing. Superseded in this catalog by Haiku 5.5. |
| Context | 1 million tokens. 128K max output, or 300K on the Message Batches API with the output-300k beta header. | Use the model card for the pinned ID. This comparison does not copy the 1M window from Haiku 5.5 onto 4.5. |
| List price | At or under 100K prompt tokens: $0.10 input, $0.50 output, $0.01 cache read. Above 100K: $0.50, $2.50, and $0.05. | Legacy card on claude.com/pricing: $1 input and $5 output per million tokens, with cache reads at $0.10. |
| Controls | Adaptive thinking. Default effort is medium. Knowledge cutoff June 2026. | Do not assume Haiku 5.5 effort settings exist on the 4.5 ID. |
| Operational risk | The newer tokenizer counts about 30% more tokens than Haiku 4.5 on the same text. Bedrock, Google Cloud, and Foundry haiku aliases can still point at 4.5. | A prompt that fit the old tokenizer can cross the 100K price tier on 5.5 because the same text counts as more tokens. |
Key insights
Concrete technical or product signals.
- Haiku 5.5 is cheaper on the short-prompt sticker and more expensive to tokenize. Re-price a real prompt before you treat the $0.10 rate as a 10x cut.
- Pin claude-haiku-5-5 in production. The haiku alias is provider-specific.
Use cases
Where this shines in production.
- Replacing a pinned Haiku 4.5 route
- Pricing subagent traffic
- Choosing a Claude Code Haiku model
Limitations & trade-offs
What to watch for.
- Product-fit comparison. No shared benchmark table is scored here.
- Haiku 4.5 context and effort controls are not copied from the 5.5 card.
Who should not choose this?
Signals that this pair is the wrong default.
- Do not assume the haiku alias is 5.5 on every cloud.
- Do not budget 5.5 as one-tenth of 4.5 without counting tokens.
- Do not disable thinking on 5.5 by copying an older request.
Final recommendation
What to do after reading the table.
Switch new calls to Haiku 5.5 and re-price one production prompt before you delete the 4.5 pin.
FAQ
Is Claude Haiku 5.5 better than Claude Haiku 4.5?
Neither Claude Haiku 5.5 nor Claude Haiku 4.5 is a universal winner. Use the comparison table and the choose-when notes, then validate on your workload.
Which is cheaper: Claude Haiku 5.5 or Claude Haiku 4.5?
Listed unit prices: Claude Haiku 5.5 At or under 100K prompt tokens: $0.10 input, $0.50 output, $0.01 cache read. Above 100K: $0.50, $2.50, and $0.05; Claude Haiku 4.5 Legacy card on claude.com/pricing: $1 input and $5 output per million tokens, with cache reads at $0.10. A lower listed unit price is not the same as a lower total workload cost—tokens, session minutes, caching, introductory rates, and add-on modes can reverse the ranking. Confirm live rates on each vendor’s official page.
Can I use both Claude Haiku 5.5 and Claude Haiku 4.5?
Yes. Many teams keep both and route by constraint. Use Claude Haiku 5.5 for New high-volume classification, routing, extraction, and subagent work, and Claude Haiku 4.5 for Pinned Haiku 4.5 calls that have not been replayed on 5.5. Confirm vendor terms before mixing them in one production workflow.