Trello is known for its long side-scrolling window, and this window can get very long when planning a substantial project. How to take a quick horizontal screenshot of such a Trello window?

The only screenshot software that hints it can do this is SnagIt. But here’s how to do it for the Opera browser without any additional software. It’s very similar for other Chrome-based Web browsers.

1. Visit Trello, allow your board to load. Position the scrolling frame at your starting point.

2. Menu | Developer | Developer Tools. This brings up the scary Developer console.

3. Ignore all the scary bits and on the console just click here…

This gives you a ‘mobile device view’ of your page, in this case the active side-scrolling frame which is the ‘meat’ of a Trello board. The view appears above the Developer console.

4. Up top you now have your mobile device preview and above this are two inputs for Dimensions, in pixels.

Change the left-hand setting to 9999. This is as high as it can go, but should be long enough for most larger Trello boards. Give it a moment to load up the entire frame, after you’ve increased the Dimensions. You should then see a mini overview of your board, as if on some crazy 6ft-long mobile device(!). It won’t be blurred, as here, but you get the idea…

5. Over in the top-right of the screen, notice the mundane three-dot icon. Click it and from its menu choose “Capture full-sized screenshot”.

6.Then click anywhere non-active in the preview. Any ‘grey bit’ should do…

A screenshot will be created and saved. It may not be a perfect capture in terms of near and far edges, but should be good enough for ‘snapshot’ archival purposes.

7. Unclick the ‘mobile device view’, and then back out of the Developer Tools panel. After a moment your browser should return to its normal view.

You’re done. You should now have a huge ‘side-scrolled’ capture of your Trello board, as a .PNG in your usual downloads folder.

The same process should work for other long horizontal frames on websites.