Claude Haiku 4.5: Anthropic's official Claude Haiku 4.5 release: Speed, cost, coding, and computer use

One-sentence takeaway

Anthropic positions Haiku 4.5 as a low-cost, high-speed model for real-time assistants, customer service, pair programming, Claude Code sub-agents, and computer use. It emphasizes coding quality close to Sonnet 4, while Sonnet 4.5 remains the frontier model for complex coding.

Test environment

• Model/entry points: Claude Haiku 4.5; Claude API, Claude Code, the app, Amazon Bedrock, and Google Vertex AI.

• Cost: $1 per million input tokens and $5 per million output tokens.

• Benchmarks and cases: SWE-bench Verified, Augment agentic coding, instruction-following for slide text, computer use, and internal safety evaluations; harnesses varied by project.

• Safety: Anthropic published an ASL-2 classification and a system card link, stating that the model showed a lower rate of problematic behavior in automated alignment evaluations.

Inputs/configuration

The release page does not disclose the complete prompts, model parameters, sample counts, repetition counts, or error details for each benchmark. It says that Haiku 4.5 reached 90% of Sonnet 4.5's performance in the Augment agentic coding evaluation, and cites product cases in hallucination, speed, and cost.

Results data

• Anthropic characterizes Haiku 4.5 as providing a coding level similar to Sonnet 4, at about one-third the cost and more than twice the speed.

• Augment agentic coding evaluation: Haiku 4.5 reached 90% of Sonnet 4.5's performance (as cited by the publisher).

• Anthropic says Haiku 4.5 outperformed Sonnet 4 on computer-use tasks and was more responsive in real-time assistants, customer service, pair programming, and multi-agent projects.

• The release page cites an instruction-following case for slide text: Haiku 4.5 at 65% versus 44% for the advanced model; the complete task set and scoring rules were not disclosed.

Conclusions

For short responses, batch extraction, real-time interaction, and divisible subtasks, Haiku 4.5's cost and latency advantages offer clear product value. Difficult planning, cross-file architecture, and critical decisions still require Sonnet/Opus or independent review.

Limitations

• All figures come from Anthropic or partner/customer cases and are official or partner-reported, with no complete public harness.

• “90% of Sonnet 4.5” is relative performance, not a 90% absolute success rate.

• Computer use and web tasks carry prompt-injection, permission, and accidental-action risks; the release page's safety evaluations do not replace production isolation.

• Pricing and performance on the release date are not guaranteed to remain stable; model aliases, cloud platforms, and rate limits may change.

Reproduction steps

1. Fix the claude-haiku-4-5 snapshot, API provider, max_tokens, tool permissions, and task set.

2. Select five task categories—short-form Q&A, batch extraction, code completion, computer forms, and sub-agents—and compare them against Sonnet 4.5.

3. Record accuracy/per-question resolved status, p50/p95 latency, input and output tokens, call count, cost, and safety incidents.

4. Add escalation/human review to critical tasks, and report Haiku-only results separately from the final results after routing.