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A free guide by Mariah Brunner ↗ INSTAGRAM ↗ TIKTOK

How to Pick the
Right Claude
Every Time

Most people use the same Claude for everything. They burn usage on simple stuff or get shallow answers on the hard stuff. There are 4 Claudes, and each one is built for different work. Here’s the cheat sheet.

The current lineup is Haiku 5.5, Sonnet 5.5, Opus 5.5 and Fable 5.1. Older ones like Sonnet 4.6, Opus 4.7 and Haiku 4.5 are now legacy. (Anthropic’s model overview)

  1. Haiku 5.5: the fastest and lightest. The usage saver.
  2. Sonnet 5.5: the daily driver. Anthropic calls it the best mix of speed and intelligence.
  3. Opus 5.5: the deep thinker for long, multi-step work.
  4. Fable 5.1: the heavy hitter for the hardest reasoning. Slowest and priciest.

How To Switch

Click the model name next to the send button and pick one. Click More models to see the rest. You can switch mid-chat, and it applies from Claude’s next reply.

Which Plan Gets Which
  1. Free: Sonnet and Haiku.
  2. Pro ($20/month, or $17/month billed yearly): adds Opus. Fable runs on pay-as-you-go usage credits.
  3. Max ($100/month) and Ultra ($200/month): everything, with Fable included for up to half your weekly limit.

Bigger models use your limit faster. On the API, Opus 5.5 costs twice what Sonnet 5.5 does, and Fable 5.1 costs 2.5x Opus. Prices change, so check Claude’s pricing page.

Sonnet 5.5: Use It For 80% Of Your Work

Sonnet is my daily driver. It’s fast and smart enough that most work never outgrows it.

Use it for emails, reports and drafts, docs, sheets and slides, normal coding, research that needs reasoning, summaries and content. Basically anything you’d ask a smart coworker.

Sonnet: Draft In My Voice
You are my writing partner. Draft a [follow-up email / report section / LinkedIn post] for me. CONTEXT: - Who it's for: [name, role, relationship to me] - What happened before: [paste the thread, call notes or key points] - What I want them to do after reading: [reply, approve, book a call] - My tone: [e.g. concise, warm, action-oriented. Paste 1 or 2 things I've written so you can match my voice] STEPS: 1. If anything critical is missing, ask me 1 question first. Otherwise go. 2. Write the draft. Keep it under [X] words. 3. Give me 2 subject line or hook options. RULES: - Plain words, short sentences, no corporate filler. - Never invent facts, numbers or promises I didn't give you. Mark anything you're unsure of as [CHECK]. - No commentary. Just the output.
Opus 5.5: When Sonnet Feels Surface-Level

Opus is built for long, multi-step work. Use it when accuracy matters more than speed, or when Sonnet’s first answer feels too shallow.

Use it for research across lots of sources, strategies and business plans, long documents where Claude has to hold a lot at once, code changes across many files, and decisions where you want a real second opinion.

Opus: Pressure-Test A Decision
You are a senior strategy advisor. I need a real second opinion, not a summary. THE DECISION: [e.g. raise prices 20% or add a cheaper tier] OPTION A: [describe] OPTION B: [describe] WHAT I KNOW: [numbers, customer feedback, constraints. Attach any docs or spreadsheets] WHAT MATTERS MOST TO ME: [e.g. cash in the next 6 months, keeping my best clients] STEPS: 1. Restate the decision in one sentence so I know you got it. 2. Pressure-test each option: the best case, the most likely case, the worst case, and what would have to be true for it to work. 3. Name the 3 assumptions I'm most likely wrong about, and how I could check each one this week. 4. Pick one. Tell me why, and what would change your mind. OUTPUT: Short headers, bullets, and a one-paragraph recommendation at the end. RULES: - Use only what I gave you or what you can verify. Label guesses as guesses. - Be direct. If both options are bad, say so and suggest a third.

Still stuck? That’s when Fable 5.1 earns its cost. Save it for the problem Opus couldn’t crack.

Haiku 5.5: The Usage Saver

Haiku is for high-volume, simple jobs that don’t need a heavy model thinking them through.

Use it for quick lookups, short summaries, sorting or labeling things in bulk, and pulling specific details out of a document.

Haiku: Sort Feedback Into Themes
Sort the items below into themes. INPUT: [paste customer feedback, survey answers, support tickets or notes, one per line] STEPS: 1. Group them into no more than [5] themes. 2. For each theme give: a 3 to 5 word name, how many items fall in it, and 1 example quote copied word for word. 3. Put anything that doesn't fit under "Other". OUTPUT: A table with columns Theme | Count | Example. Then one line naming the biggest theme. RULES: Don't rewrite or summarize the quotes. Don't add advice. No commentary. Just the table.
Extended Thinking Is Now Effort

The old Extended Thinking toggle is gone on the new models. On Haiku 5.5, Sonnet 5.5, Opus 5.5 and Fable 5.1, thinking is always on in the Claude app. What you control is effort, how hard Claude works before it answers. (Claude’s effort settings)

  1. Change it. Click the model name, then Effort, and pick a level. Each model marks its default.
  2. Low or Medium for routine tasks. They stretch your usage further.
  3. High is the best overall balance. Extra high and Max are for the hardest problems.

Before you jump to a bigger model, try raising the effort on the one you’re already in.

5 Habits That Stretch Your Usage

01

Edit your message instead of sending a follow-up

If the answer is off, hover over your last message and click the pencil. Editing branches the chat, so the wrong answer doesn’t ride along as context.

02

Batch related tasks into one message

Anthropic’s own tip. Put three related asks in one numbered message instead of three separate ones.

03

End prompts with "No commentary. Just the output."

It cuts the preamble, so replies come back shorter on simple tasks.

04

New topic, new chat

Conversation length affects your usage, because Claude re-reads the thread each time. When you switch topics, start fresh.

05

Put files you reuse in a Project

Reference docs in a Project’s knowledge get cached, and reused cached content counts less against your limits. On a paid plan, check where you stand anytime in Settings, then Usage. (Usage limit best practices)