As developers, we compare files constantly — reviewing pull requests, checking config changes, spotting bugs between versions. But not all diff tools are created equal. Some require installation, some upload your files to remote servers, and some just don't support the formats you need. Here's a rundown of the best free file diff tools available in 2026, so you can pick the right one for your workflow. 1. FileDiffs — Best for Privacy & Format Support If you work with sensitive files or just don'