- Why you won't find one official number
- The example numbers, for scale
- Warn, disable and max: the three stages
- Checking the real limits on your own board
- Examples, not promises
- Working with checklists day to day
- Breaking work down in other tools
- My advice if your cards keep growing
- Frequently asked questions
Trello doesn't publish one fixed checklist cap. Its developer docs show per-card and per-board checklist limits in an example API response: a warning at 450 and a block at 475 checklists per card, and 14400 and 15200 per board. Trello says limits vary by board and account, so treat those numbers as examples, not promises.
Why you won't find one official number
Search for a checklist limit and you'll see numbers repeated with great confidence. The honest answer is that Trello doesn't publish a single fixed one. What it does publish, in its developer documentation, is an example of the limits data its API can return, and it's careful to say those examples aren't the documented limits. Limits may vary by board and by account.
So any number below is a sign of scale, not a promise for your board.
The example numbers, for scale
| Object | Example response | Notes |
|---|---|---|
| Checklists per card | Warns at 450, blocks at 475 | Example only; varies by board and account |
| Checklists per board | Warns at 14400, blocks at 15200 | Example only; varies by board and account |
| Attachments per card | Warns at 900, blocks at 950 | Example only |
| Stickers per card | Warns at 63, blocks at 67 | Example only |
| Open cards per board | Warns at 4500, blocks at 5000 | Example only |
| Items per checklist | Not stated | No limit given in the pages I've read |
Even taking the examples as a guide, very few small teams will come near hundreds of checklists on one card. If you're anywhere close, the card is doing the job of a whole list, and it's time to split it.
Warn, disable and max: the three stages
The limits data uses two named thresholds, plus a hard ceiling:
- warnAt is the count where Trello clients start warning you.
- disableAt is the count where Trello clients stop letting users add that kind of object.
- Above disableAt there's a maximum. Beyond it, the API returns an error when more objects are added, with the status maxExceeded.
That staging is useful. You'll normally get a warning well before anything stops working.
Checking the real limits on your own board
Because limits vary, the reliable way to know yours is to ask Trello. The REST API can return a board's limits when you add ?fields=limits to the request, covering boards, cards, checklists, labels and lists. It works on a card too. If you've got someone technical on the team, it's a two-minute check that beats guessing.
Examples, not promises
The Atlassian Trello developer docs say it directly: the only numbers published are example API responses, they aren't the documented limits, and they vary by board and account. The pages I've read also give no limit at all for items inside a single checklist, so I won't invent one. If you build a process that depends on a specific number, check your own board first.
Working with checklists day to day
Most of the practical questions are about everyday use rather than limits:
- Add a checklist from the card with the Checklist button.
- Paste in items one per line to create many at once, which is the quickest way to load a long template.
- Convert a checklist item into its own card when it grows into a bigger job.
- Watch the card front: it shows the total number of checklist items and turns green when they're all done.
- In a Premium Workspace, advanced checklists let you assign a person and a due date to each item.
One warning worth repeating: deleting a checklist or a checklist item is permanent, and there's no way to recover it. If you're tidying up, convert anything you might need into a card first. For more on organising boards so cards don't overflow, my guide to planning with the Trello calendar view helps.
Breaking work down in other tools
Notion uses sub-items to break tasks into smaller pieces that can be scoped, assigned and tracked, and they're visible in all database views.
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Jira treats sub-tasks as work items, and Atlassian says all sub-tasks must be marked Done before a sprint can be completed.
My advice if your cards keep growing
Don't plan around a checklist number, because Trello doesn't give a fixed one. If a card has more than a handful of checklists, turn the big ones into cards of their own, and use ?fields=limits if you need to know your board's real ceiling. For a wider way of running projects on boards, my Trello marketing plan shows a cleaner structure.
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Frequently asked questions
How many checklists can a Trello card have?
Trello's developer example shows a warning at 450 and a block at 475 per card, but Trello says limits vary and the example isn't the documented limit.
How do I check my own limits?
Call the REST API with ?fields=limits on a board or card to read the limits for that object.
Can I recover a deleted checklist?
No. Trello says deletion is permanent.
Can I add many checklist items at once?
Yes. Paste items one per line into the add item field and press enter.
Can checklist items have owners and due dates?
In a Premium Workspace, advanced checklists let you assign a person and a due date.
