Claude 4 Sonnet vs Claude 3.5 Haiku
Compare pricing, context windows, and strengths for Claude 4 Sonnet by Anthropic and Claude 3.5 Haiku by Anthropic - and see how to put either to work in Appaca.
Claude 4 Sonnet
A balanced-hybrid reasoning model tuned for everyday assistant and high-volume tasks.
View Claude 4 SonnetClaude 3.5 Haiku
A fast, affordable model matching Claude 3 Opus on many tasks while delivering major improvements in coding, accuracy, and tool use.
View Claude 3.5 HaikuClaude 4 Sonnet vs Claude 3.5 Haiku at a glance
Specs and pricing side by side, from the Appaca AI models directory.
| Spec | Claude 4 Sonnet | Claude 3.5 Haiku |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Model type | Text | Text |
| Context window | 1M tokens | 200K tokens |
| Input price | $3 / 1M tokens | $0.8 / 1M tokens |
| Output price | $15 / 1M tokens | $4 / 1M tokens |
| Status | Superseded by Claude 4.5 Sonnet | Superseded by Claude 4.5 Haiku |
How Claude 4 Sonnet and Claude 3.5 Haiku differ
What the numbers mean in practice when choosing between Claude 4 Sonnet and Claude 3.5 Haiku.
-
Claude 3.5 Haiku is 73% cheaper on input tokens ($0.8 vs $3 per million), which adds up quickly in document-heavy workloads.
-
Claude 3.5 Haiku is 73% cheaper on output tokens ($4 vs $15 per million) - the bigger factor for tools that generate long documents.
-
Claude 4 Sonnet's 1M tokens context window is roughly 5x larger than Claude 3.5 Haiku's 200K tokens, so it can work across bigger codebases, contracts, or archives in one pass.
-
Claude 4 Sonnet has been superseded by Claude 4.5 Sonnet - for new builds, consider the newer model first.
-
Claude 3.5 Haiku has been superseded by Claude 4.5 Haiku - for new builds, consider the newer model first.
Strengths side by side
Where each model shines, according to benchmarks and provider positioning.
Claude 4 Sonnet
- Hybrid reasoning: supports both fast (“near-instant”) and extended thinking modes.
- Optimised for responsiveness, cost and high-volume production workloads.
- Strong coding performance relative to prior Sonnet versions (improved over Sonnet 3.7).
- Available even in free tiers (alongside paid plans).
- Better suited for general-purpose use and agents where speed + cost-efficiency matter.
Claude 3.5 Haiku
1. Intelligence & Benchmark Performance
- Matches Claude 3 Opus (previous largest model) on many intelligence tasks.
- Surpasses Claude 3 Opus on multiple evaluations despite being a smaller, faster model.
- Major improvements across every skill category vs previous Haiku.
2. Coding Strength
Scores 40.6% on SWE-bench Verified, outperforming:
- Claude 3.5 Sonnet (original version)
- GPT-4o
- Many agent-driven systems
Excellent for engineering assistants, agent coding tasks, and bug fixing.
3. Speed & Latency
- Same speed class as Claude 3 Haiku (ultra-fast).
- Ideal for real-time interactions, high request volumes, and UI responsiveness.
4. Tool Use & Instruction Following
- Better at following instructions than previous Haiku.
- Stronger at tool use accuracy, making it reliable for agents and workflows.
5. Best Use Cases
- High-volume, low-latency tasks
- User-facing products
- Sub-agent tasks in larger workflows
- Processing large structured datasets (pricing, inventory, purchase history)
- Rapid content or code generation where speed matters
Use Claude 4 Sonnet or Claude 3.5 Haiku - or both
Appaca is the AI workspace for operators. Build internal tools and AI co-workers powered by Claude 4 Sonnet or Claude 3.5 Haiku - connected to your real data and ready for your whole team. No code, no deployment.
Describe it, and it's built
Tell the Appaca agent the internal tool you need and it builds a working app powered by Claude 4 Sonnet or Claude 3.5 Haiku. No code, no API keys, no deployment.
Switch models without rebuilding
Start on Claude 4 Sonnet, test the same tool on Claude 3.5 Haiku, and keep whichever performs better - the rest of your app stays exactly as it is.
Automated for the whole team
Schedule tools to run on autopilot - daily digests, weekly reports, real-time triggers - and share them with your whole team from one workspace.
Describe it, and it's built
Tell the Appaca agent what your team needs and it builds a working app powered by Claude 4 Sonnet or Claude 3.5 Haiku - connected to the tools you already use.
Related comparisons
See how Claude 4 Sonnet and Claude 3.5 Haiku stack up against other models in the directory.
FAQs
Claude 3.5 Haiku is generally cheaper: $0.8 input / $4 output per million tokens, versus $3 / $15 for Claude 4 Sonnet. Actual cost depends on how many tokens your workload reads and writes.
Claude 4 Sonnet has the larger context window at 1M tokens, compared to 200K tokens for Claude 3.5 Haiku. A larger window means the model can consider more text at once - useful for long contracts, codebases, or months of records.
It depends on the job. Compare the pricing, context window, and strengths above against your workload - and remember the choice isn't permanent. In Appaca you can build a tool on Claude 4 Sonnet, test the same tool on Claude 3.5 Haiku, and switch at any time without rebuilding anything.
Yes. Appaca is a no-code AI workspace: describe the internal tool your team needs and the Appaca agent builds it as a working app powered by Claude 4 Sonnet, Claude 3.5 Haiku, or any other model in the directory - with a built-in database, team access, and integrations. No API keys to wire up and nothing to deploy.
Build AI tools with Claude 4 Sonnet or Claude 3.5 Haiku
Describe the tool your team needs and get a working app powered by the model you choose - with a built-in database, team access, and integrations. No code, no deployment.