Claude offers three models with different personalities — Opus 4.8, Sonnet 4.6, and Haiku 4.5. The smartest model is not always the right answer. Pick based on the task's difficulty, speed, and cost. This guide lays out how the three differ and when to use which.
The differences at a glance
Here are the core specs (Claude API, per official docs). Pricing is input / output per 1M tokens.
- Opus 4.8 — most capable. 1M context / 128K output tokens. $5 / $25.
- Sonnet 4.6 — balanced. 1M / 64K tokens. $3 / $15.
- Haiku 4.5 — fastest. 200K / 64K tokens. $1 / $5.
Note: pricing and specs are current as of June 2026 and may change. Check the official docs for the latest.
Opus 4.8 — for hard work
Best for the most complex reasoning, long-horizon agentic coding, and tasks needing high autonomy. Great when accuracy is paramount or you must handle a lot at once. In return it is the most expensive and overkill for light work.
Sonnet 4.6 — for most work
Its balance of speed and intelligence makes it a solid default for most everyday work. Use it broadly for writing, coding, and analysis at a lower cost than Opus. If you are unsure which to use, start here.
Haiku 4.5 — fast and lightweight
The fastest of the three. Good when quick responses matter, when you process simple, repetitive tasks in bulk, or when you need to save on cost. Note its context (how much it reads at once) is the smallest at 200K tokens.
How to choose
- Task is hard and accuracy matters → Opus 4.8
- General work, a solid balance → Sonnet 4.6
- Speed, volume, cost savings → Haiku 4.5
In claude.ai chat you can switch models on screen; via the API you specify a model ID (e.g. claude-opus-4-8, claude-sonnet-4-6). Check the official docs for each model's exact ID. Note there is also a higher tier above these three (Fable 5), but its availability terms differ from the standard models and need separate confirmation.
Related: Opus 4.8 New Features Guide · Opus 4.8 Complete Guide.