Visual Diff Merge

Visual Diff-Merge is an open-source, web-based tool for comparing and merging code in a clean, responsive split-view interface. Built with PHP and JavaScript, it supports syntax highlighting for over 180 programming languages — including HTML, PHP, JavaScript, Python, TypeScript, SQL, YAML, and more. It offers four comparison modes: browse files from a server directory, upload local files, paste code snippets directly, or compare content from two URLs. Changes are displayed side by side with interactive merge selection, letting you pick exactly which modifications to keep. Available as a self-hosted installation (PHP 7.4+, Apache/Nginx) or instantly usable online at visual-diff-merge.miglisoft.com — no setup needed. Supports dark and light themes, internationalization, and is fully configurable via a single PHP config file. Licensed under GPL-3.0.