What Are the System Requirements for Meld?

Meld's documented requirements are Python 3.6, GTK+ 3.22, GLib 2.36, PyGObject 3.36, GtkSourceView 4.0, and pycairo. These are the runtime dependencies listed on meld.app for running the visual diff and merge tool. If your system provides these libraries, Meld should run; if any are missing or too old, you'll need to upgrade them or use a packaged build that bundles them.

The documented requirements

The site lists these as the requirements for Meld generally. It also notes that the current README file should be consulted for development and build requirements, which can differ from what an end user needs to run a packaged release.

What this means in practice

• You usually don't install these by hand. Meld is packaged for most Linux/Unix distributions and is also available on Flathub, so the package manager or Flatpak resolves the dependencies for you. On Windows, the site directs users to download the installer. On macOS, Meld is not yet officially supported, though semi-official builds exist via Homebrew, MacPorts, or Fink.
• Version mismatches are the main failure mode. If your distribution ships an older GTK+ or PyGObject than the listed minimums, a source build may fail or Meld may not start. Checking your package versions before building from source is the practical step.
• The requirements describe the app, not a specific release. The site lists Meld 3.24.0 as the current stable release (dated 20 June 2026), but the requirement list is presented as Meld's general requirements rather than being tied to that version number.

Checking your environment

On a Linux system, you can confirm the key pieces before installing or building:

python3 --version        # expect 3.6 or newer
pkg-config --modversion gtk+-3.0        # expect 3.22 or newer
pkg-config --modversion glib-2.0        # expect 2.36 or newer
pkg-config --modversion gtksourceview-4 # expect 4.0 or newer

Expected result: each command prints a version at or above the minimum in the table. If a command reports "not found," that library isn't installed or isn't discoverable by pkg-config.

For PyGObject and pycairo, which are Python modules, you can check from Python:

python3 -c "import gi; print(gi.__version__)"
python3 -c "import cairo; print(cairo.version)"

Common sticking points

• GtkSourceView 4.0 vs. 3.x. Meld's requirement is the 4.0 series. A system carrying only GtkSourceView 3.x won't satisfy it, and this is a frequent reason a source build fails on older distributions.
• PyGObject version vs. GTK+ version. These are separate numbers. Having a recent GTK+ doesn't guarantee a recent PyGObject, and Meld lists PyGObject 3.36 specifically.
• macOS caveat. Because macOS support is described as not yet official, the requirement list may not translate cleanly to the semi-official Homebrew/MacPorts/Fink builds. Treat those builds as the supported path there rather than compiling against the listed versions yourself.
• No automatic updates or portable installs. The site states Meld does not yet support automatic updates or portable installs, so plan to manage upgrades through your package manager or by reinstalling.

If you're unsure whether a problem is a dependency issue, the project asks users to open an issue on GNOME's GitLab instance or ask on the discussion board.