Meld

Getting started comparing folders

Meld lets you compare two or three folders side-by-side. You can start a new folder comparison by selecting the File ▸ New... menu item, and clicking on the Directory Comparison tab.

Your selected folders will be shown as side-by-side trees, with differences between files in each folder highlighted. You can copy or delete files from either folder, or compare individual text files in more detail.

The folder comparison view

The main parts of a folder comparison are the trees showing the folders you're comparing. You can easily move around these comparisons to find changes that you're interested in. When you select a file or folder, more detailed information is given in the status bar at the bottom of the window. Pressing Enter on a selected file, or double-clicking any file in the tree will open a side-by-side file comparison of the files in a new tab, but this will only work properly if they're text files!

There are bars on the left and right-hand sides of the window that show you a simple coloured summary of the comparison results. Each file or folder in the comparison corresponds to a small section of these bars, though Meld doesn't show Same files so that it's easier to see any actually important differences. You can click anywhere on this bar to jump straight to that place in the comparison.

Navigating folder comparisons

You can jump between changed files (that is, any files/folders that are not classified as being identical) with the Changes ▸ Previous change and Changes ▸ Next change menu items, or using the corresponding buttons on the toolbar.

You can use the Left and Right arrow keys to move between the folders you're comparing. This is useful so that you can select an individual file for copying or deletion.

States in folder comparisons

Each file or folder in a tree has its own state, telling you how it differed from its corresponding files/folders. The possible states are:

Folder comparison states

State

Appearance

Meaning

Same

Normal font

The file/folder is the same across all compared folders.

Same when filtered

Italics

These files are different across folders, but once text filters are applied, these files become identical.

Modified

Blue and bold

These files differ between the folders being compared.

New

Green and bold

This file/folder exists in this folder, but not in the others.

Missing

Greyed out text with a line through the middle

This file/folder doesn't exist in this folder, but does in one of the others.

Error

Bright red with a yellow background and bold

When comparing this file, an error occurred. The most common error causes are file permissions (i.e., Meld was not allowed to open the file) and filename encoding errors.

You can filter out files based on these states, for example, to show only files that have been Modified. You can read more about this in File differences filtering.

Finally, the most recently modified file/folder has an emblem attached to it.