Trello Attachment Size Limit: 10 MB, 250 MB and Linked Files

Every card attachment limit in one table

Item	Limit	Applies to
File uploaded from your computer	10 MB per attachment	Standard setup
File uploaded from your computer	250 MB per attachment	Members on upgraded plans
File attached via a link	10 MB cap doesn't apply	All plans
Total account data storage	No limit	Every plan
Animated GIF shown as an animation on a card cover	Under 300 pixels wide and under 5MB	Card covers
Local or shared-drive file (file:// link)	Not supported without uploading	All plans

Every row comes from Atlassian Support's page on adding attachments to cards. The key thing to notice is that the limit is per file, never per account. You can keep adding files to boards for years without running into a storage wall, as long as each single upload fits.

Uploads versus links: the difference that decides everything

There are two ways to put a file on a card, and they behave very differently. When you attach a file from your computer, Trello makes a copy of it and stores it in Amazon S3. That copy is what the 10 MB cap, or the 250 MB cap for upgraded members, applies to.

When you attach something from Confluence, Jira, a cloud drive or another web source, the card only stores a link to that page. No copy is made, so the upload cap doesn't apply at all. That's why the usual answer to a file that's too big is simple: put it in your cloud storage and attach the link instead.

The trade-off is ownership. An uploaded file lives inside the card, so it's there even if someone tidies up the shared drive. A linked file depends on wherever it's hosted, and if that folder moves or the sharing settings change, the card just holds a broken link.

What happens when a file is over the cap

The upload won't go through. Your options are to shrink the file, move to an upgraded plan if you're on the standard setup and need room for files up to 250 MB, or host it elsewhere and attach the link. For most teams the link route is quickest, because the total storage question never comes up.

There's one route that won't work: pointing a card at a file on your own network. Shared drive attachments, FTP-stored files and file:// links can't be used, because local files have to be uploaded to be attached. If your agency keeps assets on an office server, you'll need to upload them or move them to a cloud drive first.

If you regularly send hefty files to clients by email as well, this guide on sending large files from Gmail covers the same problem from the inbox side.

Clients outside the board can't open uploaded files

This is the part that catches agencies out. Uploaded attachments now check user authorization before they display. So if you copy an attachment link and send it to a client who isn't a member of that board, they're prompted to log in and the file won't display. Atlassian Support (Trello) spells this out on the attachments page, along with the exception: attachments and previews on public boards stay accessible without an account.

In practice, if a client needs a file, either invite them to the board, share the file from your cloud storage directly, or make sure the board is public, which most client work shouldn't be. Don't rely on forwarding an attachment link and hoping it opens.

Deleting files and cards

Deleting an attachment permanently removes the uploaded file from Amazon S3, and deleting a card also deletes any files attached to it. There's no separate recycle bin for attachments mentioned on the page, so if a card holds the only copy of a signed contract, download it before you clear the board out. Linked files are safe from this, since the card never held the file itself.

If you plan work on a timeline, the calendar view for your boards is a tidy way to see which cards hold deliverables before you archive or delete anything.

Card cover GIFs have their own rule

Animated GIFs show as animations on card covers only when they're under 300 pixels wide and under 5MB. Bigger GIFs still attach, they just won't animate on the cover. It's a small thing, but it explains why a team mascot GIF sits there frozen.

When files are too big for any card

Notion's help page says that, as of Nov 2026, every uploaded file on its Free Plan must be under 5MB, while on upgraded plans PDFs must be under 20MB and PNG or JPG images under 5MB. That's tighter than a card upload for most file types.

Dropbox Transfer sends files up to 100 GB, upgradable to 250 GB, without taking up space in your account. For a video master or a large design pack, that's a sensible route: send the transfer, then attach the link to the card so the team can find it.

My advice for teams that share big files

Treat cards as the place where work is tracked, not where heavy files are stored. Keep large assets in your cloud storage, attach them as links, and invite clients to the board if they need to see uploads. You'll never hit the cap, nothing vanishes when a card is deleted, and nobody gets a login screen instead of their proofs.

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Frequently asked questions

What is the Trello attachment size limit?

10 MB per file uploaded from your computer, and 250 MB per attachment for members on upgraded plans, as the attachment documentation states.

Can I attach a bigger file to a Trello card?

Yes, by attaching it as a link. The upload limit doesn't apply to files attached via a link.

Is there a limit on total Trello storage?

No. The vendor states there's no account data storage limit in any plan; only the per-attachment size applies.

Can I attach a file from a shared drive or server?

Not directly. Local files have to be uploaded to be attached, so shared drive, FTP and file:// links can't be used.

Will a client outside my board see an uploaded attachment?

Not without logging in with board access, since uploaded attachments check authorization. Attachments on public boards stay accessible.