Claude Haiku 4.5
Anthropic's fastest model with near-frontier intelligence — 2x the speed of Sonnet 4, one-third the cost, and SWE-bench Verified 73.3%. The right Anthropic choice for high-volume chat, customer support, and rapid iteration.
Model Specs
- Released
- Oct 2025
- Context window
- 200K tokens
- Max output
- 64K tokens
- Capabilities
- extended-thinkingfunction-callingfast-inferencemultimodal
- Modalities
- textvision
About this model
Claude Haiku 4.5 is Anthropic's fastest and most affordable model, released on October 15, 2025. Anthropic's positioning is sharp: similar coding performance to Claude Sonnet 4 at one-third the cost and more than twice the speed. The model surpasses Sonnet 4 on computer-use tasks (controlling browsers and apps) and excels at chat assistants, customer service agents, and pair programming where responsiveness matters as much as raw intelligence.
On the public benchmarks Anthropic reports, Haiku 4.5 reaches 73.3% on SWE-bench Verified and 40-42% on Terminal-Bench (depending on whether extended thinking is on). The 73.3% SWE-bench is only ~4 points behind Sonnet 4.5's 77.2% — close enough that for most coding tasks, the speed and cost advantage of Haiku makes it the better choice.
On Renas AI, Claude Haiku 4.5 costs 0.025 credits per word — about 2.5x cheaper than Sonnet 4.5 (0.07) and 14x cheaper than Opus 4.1 (0.35). Pick Haiku for chatbots, customer support automation, high-volume content workflows, rapid coding iteration, and any task where 2-3x faster response time meaningfully improves the user experience. For complex agentic chains or critical code where the 4-point benchmark gap matters, step up to Sonnet 4.5.
Key Strengths
2x faster than Sonnet 4
Anthropic explicitly markets Haiku 4.5 as more than twice the speed of Sonnet 4. For chat assistants, customer-facing agents, and any user-interactive workflow, this matters as much as raw quality.
One-third the cost of Sonnet at near-Sonnet quality
Pricing is $1/M input, $5/M output — vs Sonnet 4.5 at $3/$15. With SWE-bench within 4 points of Sonnet 4.5 (73.3% vs 77.2%), Haiku is the cost-efficiency winner.
Surpasses Sonnet 4 on computer use
Anthropic reports Haiku 4.5 actually beats the older Sonnet 4 on computer-use benchmarks — controlling browsers, file systems, and apps. For agentic automation workflows that don't require Sonnet 4.5's specific advantages, Haiku is competitive.
200K context with extended thinking
Same 200K context window as Sonnet 4.5 — enough for entire codebases, long documents, and multi-document synthesis. Extended thinking is supported for harder problems.
Polished Anthropic writing voice
Like the rest of the Claude family, Haiku 4.5 has Anthropic's characteristic clear, structured writing voice. Often a better fit than budget alternatives for content that will be published as-is.
Native vision input
Multimodal text + image input at no extra credit cost. Same capabilities as Sonnet and Opus — useful for UX reviews, document OCR + analysis, technical figure interpretation.
Benchmarks
How it compares
Haiku 4.5 sits in the affordable Anthropic tier alongside cost-comparable models from other providers. Each makes a different trade-off on speed, cost, and ecosystem.
| vs. Model | Verdict | Outcome |
|---|---|---|
| Claude Sonnet 4.5 | Sonnet 4.5 has higher SWE-bench (77.2% vs 73.3%), longer continuous task focus (30+ hours), and Anthropic's full suite of computer-use features. Haiku is 3x cheaper and 2x faster. For high-volume chat or rapid iteration, Haiku wins; for critical code or complex agentic chains, Sonnet 4.5 justifies the cost. | Depends |
| GPT-5 Mini | GPT-5 Mini is 2.5x cheaper than Haiku (0.01 vs 0.025 credits per word) and has a larger 400K context. Haiku has Anthropic's polished writing voice, computer-use support, and stronger SWE-bench. For pure cost efficiency, GPT-5 Mini wins; for writing quality and Anthropic ecosystem features, Haiku is the better pick. | Depends |
| Grok 3 Mini | Grok 3 Mini is the cheapest text model on Renas at 0.003 credits per word — 8x cheaper than Haiku. Grok also offers real-time X (Twitter) data access. Haiku has substantially stronger coding benchmarks and writing quality. For current-events and minimum cost, Grok; for general purpose with quality, Haiku. | Wins most cases |
Pros
- More than 2x the speed of Sonnet 4
- One-third the cost of Sonnet 4.5
- Near-frontier intelligence (SWE-bench 73.3% — only 4 points behind Sonnet 4.5)
- Surpasses Sonnet 4 on computer-use tasks
- 200K context window with extended thinking support
- Native vision input at no extra credit cost
- Polished Anthropic writing voice
Things to consider
- Behind Sonnet 4.5 on hardest coding benchmarks (~4 points SWE-bench gap)
- More expensive than budget alternatives like Grok 3 Mini or GPT-5 Mini
- Doesn't reach the 30+ hour task-focus capability of Sonnet 4.5
- Less benchmark coverage on pure-reasoning evals (GPQA, AIME) than OpenAI models
Best use cases
Customer support chatbots
High-volume conversational workflows where speed matters and complexity is moderate. Haiku's 2x speed advantage means snappier user experience without sacrificing too much capability.
Pair programming and rapid coding iteration
When you're rapidly iterating on code with the model, Haiku's responsiveness keeps the flow tight. The 4-point SWE-bench gap vs Sonnet rarely matters during exploration.
Content drafting at scale
Blog post drafts, ad copy variations, social media posts. Haiku's lower cost makes high-volume drafting economical, then promote winners to Sonnet for polish if needed.
Document Q&A and search
Index documents into context, answer specific questions. The 200K window handles realistic inputs and Haiku's speed makes interactive Q&A loops feel responsive.
Computer-use automation
Browser automation, app control, multi-step workflows. Haiku 4.5 surpasses Sonnet 4 on computer-use benchmarks while staying cheaper and faster than Sonnet 4.5.
Educational and tutorial content
Course material drafts, explanatory content, beginner-friendly tutorials. Anthropic's clear writing voice fits educational use cases well.
How to use it on Renas AI
- 1
Step 1
Pick the surface that fits the task
Haiku 4.5 is available in AI Chat, Blog Wizard, AI Editor, and the WordPress plugin on Renas AI. For high-volume customer-facing chatbots, AI Chat with Personas is the right surface; for content drafting, Blog Wizard.
- 2
Step 2
Switch from the default Sonnet 4.5
Sonnet 4.5 is the Renas chat default. Switch to Haiku 4.5 in the model picker when speed and cost matter more than the marginal quality gain. For most everyday chat, Haiku is sufficient and noticeably faster.
- 3
Step 3
Provide context and constraints
Same prompting style as Sonnet — paste documents, describe the task, list constraints. The 200K context fits realistic inputs in one message; speed advantage means you can iterate faster within the same budget.
- 4
Step 4
Promote critical work to Sonnet 4.5
When Haiku produces output that's almost-but-not-quite right, regenerate the same prompt on Sonnet 4.5 for the final version. Two-stage workflow: Haiku for exploration and bulk, Sonnet for the final polish.
Pricing
Pricing on Renas AI
Pay-as-you-go credits, no API keys, no rate limits.
~400,000 words on a 10,000-credit Spark plan
Frequently asked questions
Other Anthropic models
Other text models on Renas AI
Fast Anthropic AI at a fraction of the cost
Use Claude Haiku 4.5 with your Renas AI subscription credits — no API key, no setup, no per-seat fees.
Try Claude Haiku 4.5