Claude 4.5 Opus vs Claude 3.5 Haiku
Compare pricing, context windows, and strengths for Claude 4.5 Opus by Anthropic and Claude 3.5 Haiku by Anthropic - and see how to put either to work in Appaca.
Claude 4.5 Opus
Anthropic's November 2025 flagship model, combining maximum capability with practical performance for coding, agents, computer use, and enterprise workflows.
View Claude 4.5 OpusClaude 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 4.5 Opus vs Claude 3.5 Haiku at a glance
Specs and pricing side by side, from the Appaca AI models directory.
| Spec | Claude 4.5 Opus | Claude 3.5 Haiku |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Model type | Text | Text |
| Context window | 200K tokens | 200K tokens |
| Input price | $5 / 1M tokens | $0.8 / 1M tokens |
| Output price | $25 / 1M tokens | $4 / 1M tokens |
| Status | Superseded by Claude 4.6 Opus | Superseded by Claude 4.5 Haiku |
How Claude 4.5 Opus and Claude 3.5 Haiku differ
What the numbers mean in practice when choosing between Claude 4.5 Opus and Claude 3.5 Haiku.
-
Claude 3.5 Haiku is 84% cheaper on input tokens ($0.8 vs $5 per million), which adds up quickly in document-heavy workloads.
-
Claude 3.5 Haiku is 84% cheaper on output tokens ($4 vs $25 per million) - the bigger factor for tools that generate long documents.
-
Both models offer the same 200K tokens context window.
-
Claude 4.5 Opus has been superseded by Claude 4.6 Opus - for new builds, consider the newer model first.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Claude 3.5 Haiku has been superseded by Claude 4.5 Haiku - for new builds, consider the newer model first.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 4.5 Opus
1. Maximum capability with more practical pricing
- Anthropic introduced Opus 4.5 as its most intelligent model, combining maximum capability with practical performance.
- It was positioned as the best model in the world for coding, agents, and computer use at launch, with pricing reduced to $5/M input and $25/M output.
2. Step-change gains for coding and advanced agent work
- Anthropic describes Opus 4.5 as state-of-the-art on real-world software engineering tests.
- It also improved everyday knowledge-work tasks like deep research, slides, and spreadsheets while staying strong on long-horizon agent workflows.
3. Better control over reasoning depth
- Opus 4.5 introduced the
effortparameter, letting developers trade off response thoroughness against token efficiency. - This made it easier to use one flagship model across both high-depth analysis and more cost-sensitive production workloads.
4. Stronger computer use and continuity
- Added enhanced computer use with a zoom action for inspecting detailed screen regions.
- Preserves prior thinking blocks across turns, helping the model maintain reasoning continuity in extended multi-step tasks.
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 4.5 Opus or Claude 3.5 Haiku - or both
Appaca is the AI workspace for operators. Build internal tools and AI co-workers powered by Claude 4.5 Opus 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 4.5 Opus or Claude 3.5 Haiku. No code, no API keys, no deployment.
Switch models without rebuilding
Start on Claude 4.5 Opus, 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 4.5 Opus or Claude 3.5 Haiku - connected to the tools you already use.
Related comparisons
See how Claude 4.5 Opus 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 $5 / $25 for Claude 4.5 Opus. Actual cost depends on how many tokens your workload reads and writes.
They are equal: both Claude 4.5 Opus and Claude 3.5 Haiku support a 200K tokens context window.
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 4.5 Opus, 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 4.5 Opus, 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 4.5 Opus 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.