Differing Reader is a Google Docs™ add-on that lets you compare two documents and immediately see exactly what's different between them. Designed for the moment when you have two versions of a document — a draft and a revision, two collaborators' versions, an original and a copy — and you need a precise, visual answer to "what changed?".

How it works

1. Install the add-on. From any Google Docs™ file, open the sidebar via Extensions → Differing Reader → Open sidebar.
2. Paste the URL of a second Google Docs™ file you have access to.
3. Click Compare.

The sidebar then displays a colored unified diff between the two documents: added lines highlighted in green, removed lines highlighted in red, and unchanged lines shown in plain text for context. The hunk markers from a standard diff format are preserved so you can quickly orient yourself in long documents. Most comparisons return in well under a second, even for documents at the upper end of Google Docs™' size limit.

Common uses

- Reviewing edits between two iterations of a draft kept in separate document (rather than relying on revision history within a single document).
- Comparing meeting notes that two different attendees captured independently and identifying where they diverge.
- Checking what changed in a shared document since you last read it, without re-reading the entire thing.
- Verifying a copy you made of an important document matches the original line for line.
- Finding small wording differences across template variants — contracts, proposals, recurring reports.
- Spot-checking translations or rewrites against an original.

Privacy and data handling

The privacy story is intentionally simple: your document text is never stored. When you click Compare, the textual content of both documents is transmitted over HTTPS to the diff backend, processed in memory using a well-established text-diff library, and discarded as soon as the result is returned to the sidebar. There is no database. There is no log of document content — the relevant request parameters are filtered out of server logs by configuration. Your text is never shared with third parties, never used for advertising, and never used to train machine-learning models, ours or anyone else's.

The add-on requests only the minimum scopes it needs to function: permission to read the contents of the two documents you explicitly point it at, permission to display a sidebar, and permission to make outbound HTTPS requests to the diff backend. It does not request access to your other documents, your Google Drive™ contents, your email, or any other Google data.

You can revoke the add-on's access at any time from your Google account permissions page.

Pricing

Differing Reader is free.

Compatibility

Works in Google Docs™ accessed through any standard web browser. Both the open document and the document you're comparing against must be Google Docs™ documents (not Word documents in Google Drive™); both must be accessible to your Google account.

Support

Bug reports, questions, and feature requests: admin@lininglink.com. The full privacy policy is at https://differingreader.com/privacy/ and the terms of service at https://differingreader.com/terms/.