◉CLAUDE LABJP
●2.1.296 — Sonnet 5.5 cache reads drop to $0.10/Mtok (was $0.20), and the MCP description limit rises to 4,096 characters●2.1.295 — Hooks gain onFailure: "block", so a failed or timed-out hook no longer lets the action through●SONNET 4.5 — Retires on the Claude API on 11/30, 51 days left. Migrate to Sonnet 5.5●Q&A — A long-running report: the console jumps back to the top of history whenever output is appended●HAIKU 5.5 — Code written for Haiku 4.5 hits a 400 error on budget_tokens●NEW — When first requests keep missing, hand over a one-page description of your work first●2.1.296 — Sonnet 5.5 cache reads drop to $0.10/Mtok (was $0.20), and the MCP description limit rises to 4,096 characters●2.1.295 — Hooks gain onFailure: "block", so a failed or timed-out hook no longer lets the action through●SONNET 4.5 — Retires on the Claude API on 11/30, 51 days left. Migrate to Sonnet 5.5●Q&A — A long-running report: the console jumps back to the top of history whenever output is appended●HAIKU 5.5 — Code written for Haiku 4.5 hits a 400 error on budget_tokens●NEW — When first requests keep missing, hand over a one-page description of your work first
← Back to Blog

Claude Haiku 3 Deprecation — Migrate by April 19, 2026

Claude HaikudeprecationmigrationAPI

Deprecation Notice

Anthropic has announced that Claude Haiku 3 (claude-3-haiku-20240307) will be retired on April 19, 2026. After this date, API requests to this model will return errors.

Who Is Affected

Developers using claude-3-haiku-20240307 in API calls. Claude.ai users are automatically switched to newer models and are not affected.

Migration Target

The successor model is Claude Haiku 4.5 (claude-haiku-4-5-20251001).

Key Differences

  • Context window: 200K tokens (unchanged)
  • Max output: 64K tokens (up from 4K in Haiku 3)
  • Extended Thinking: Supported (not available in Haiku 3)
  • Pricing: Input $1 / Output $5 per million tokens (higher than Haiku 3 but justified by performance improvements)

Migration Steps

Simply change the model ID in your API code.

# Before
model="claude-3-haiku-20240307"
 
# After
model="claude-haiku-4-5-20251001"
# Or use the alias
model="claude-haiku-4-5"

Things to Watch

  • Haiku 4.5 has much larger max output, so review your max_tokens settings
  • Pricing has changed, so update your cost estimates
  • Enabling Extended Thinking incurs additional costs

Summary

Complete your migration by April 19, 2026. With significantly improved performance, Haiku 4.5 offers substantial benefits.