Models, limits & cost

The single most useful habit on the free tier: knowing which AI model to reach for, and when. Most beginners burn through their daily limit on the strongest model doing work a cheaper one would have done faster — and then can't work for hours. Here's how to avoid that.

The three models, in plain words

You'll meet a small family of models. They trade depth against speed and cost — the deeper one "thinks" harder but is slower and uses up more of your allowance.

ModelThink of it asGood for
HaikuThe quick oneFast, cheap, light tasks — short answers, simple lookups, quick edits.
SonnetThe workhorseEveryday building — writing HTML/CSS, wiring up an automation, routine edits. Fast and plenty capable.
OpusThe deep thinkerThe hard, ambiguous calls — planning, untangling a gnarly bug, judgment that needs real reasoning.
There's nothing to memorise here. The names matter less than the instinct: reach for the lightest model that can do the job, and only level up when it actually struggles.

The rule: volume → cheap, leverage → strong

Here is the whole policy in one line:

Volume → a cheap model. Leverage → a strong one.

Switching mid-session

You don't pick a model once and live with it. Switch whenever the work changes character — type the command right in the chat:

/model sonnet     # routine building — fast and cheap
/model opus       # stuck on something hard — bring in the deep thinker
/model opusplan   # let it auto-switch: plan strong, build fast

A natural rhythm: stay on sonnet for the steady work, flip to opus the moment you hit something that genuinely needs untangling, then flip back. Or just run opusplan and let it decide for you.

Managing your limits without frustration

On the free tier you have a daily allowance. The way to never feel cornered by it:

A note that won't go out of date

Model names are stable aliases. Words like opus, sonnet, haiku and opusplan point to the current recommended version and roll forward on their own as new generations ship — so this lesson doesn't rot. Wherever you can, write your instructions with the alias, never a dated version string. (Specific version details on this page are valid as of 2026-06-26; the aliases themselves keep updating without you.)

Where next