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Hide Activity Details for Trello icon

Hide Activity Details for Trello

When I first made this extension, there was no way to hide all the activity details on cards. The list was full of entries like “So-and-so moved this from X list to Y list” and “So-and-so completed X item on this card”. Useful comments left by users got lost.

Since that first release, Trello added a “Hide Details” button which hides activity by default on all cards. Which is great! The only trouble is that this choice is not remembered if you log out or clear the cookies on your browser. This extension activates the Hide Activity button, if’s displayed, when you open a card.

Trello card showing all the activity entries Trello card with all the activity entries hidden
before and after

Version 2

The previous version of this extension hid all the unnecessary activity well enough, but unfortunately made it impossible to view activity again without disabling the extension. And due to the way Trello works, older comments might not have been loaded.

Version 2 hides activity in a much smarter way. Instead of blocking them on the page, it triggers Trello’s own “Hide Details” button — which means that all comments are loaded by default and you can view activity again if you want to with the “Show Details” button. When you open the card later, activity will be hidden again.

Get it


Get the add-on


Get it from Opera add-ons


Available in the Chrome web store

User script

Also available as a user script. (Legacy: version 1.2, download script)

Contact me

You can message me on Twitter (@beingmrkenny) or email me at beingmrkenny@gmail.com ✉️


This extension is only tested in the most recent versions of Chrome, Firefox and Opera.

For security reasons, I requested a transfer of this extension from my personal account (beingmrkenny@gmail.com) to a dedicated developer account (beingmrkenny.extensions@gmail.com) on 8 August 2017 (Chrome only). At time of writing, the transfer had not yet taken place.

I cannot guarantee that this extension will not interfere with other extensions or add-ons to Trello. If you notice an issue, please get in touch.

Security and Privacy

An extension I use was hacked recently: code was added to insert ads into webpages. Not so serious, but it could have been at lot worse.

Extensions can be hacked if an attacker gains access to the developer account which publishes them. The risk of that happening is very small. If you’re on Chrome, my Google account is secured with 2-factor auth (meaning even with my password my account can’t be accessed). If you’re on Opera and Firefox, they have human code review processes that check for this kind of thing, so even if someone got into my account, they wouldn’t be able to publish malicious code.

How to check you’re safe

By checking the version number, you can be sure that you have the authorised version of Hide Activity Details for Trello. It is impossible to publish a new version without increasing this number. You’ll find it listed in your browser next to the extension name, and the latest authorised version number will always be available on this page below.

The number in your browser should be the same as or less than the one listed on this page. If it is the same, you have the latest version. If it is less, it means a new version has been published but you have not received it yet. If the version in your browser is greater than the one listed below, uninstall the extension, report it to Google, Opera or Mozilla, and please get in touch with me also. Uninstalling also deletes any saved data for that extension which may have been compromised.

In the interests of transparency, I have detailed what permissions this extension requires, and why, along with any data that is sent on your behalf. Any changes in the permissions that this extension requires will be noted on this page.

Permissions and data


If you’d like to help out, the code for this extension can be found on Github at https://github.com/beingmrkenny/HideActivityForTrello

Version history

Dates refer to when the extension was submitted. Actual release dates may vary due to review processes.