Comparing Text Without Leaving the Browser
Paste two versions and see additions, deletions and changed lines highlighted side by side or as a unified diff. Comparison runs locally, so config files with secrets or unreleased copy stay on your machine. The ignore-whitespace and ignore-case switches help when the only differences are formatting noise.
Under the hood this is the same family of algorithms git uses to build commits - how Myers diff finds the minimal edit script is walked through in diff algorithms explained. If both inputs are JSON, the JSON Diff tool gives better results: it compares by key, so reordered properties do not show up as changes.