diffesq.

About Diffesq

What it is, who makes it, and how it works.

What is Diffesq?

Diffesq is a file comparison tool that runs entirely in your web browser. It shows exactly what changed between two files — Word documents, PowerPoint decks, PDFs, Excel workbooks, CSV, JSON, YAML, XML, plain text, Markdown, images, and data files such as Parquet, SQLite, JSON Lines, and Arrow — and between two whole folders. Files are processed locally on your device and are never uploaded to a server.

Who makes it?

Diffesq is built and operated by LoudFoam LLC, a US company. You can reach us at [email protected].

How is it different?

  • Private by design. Parsing, comparison, and report generation all run in your browser. There is no upload step and no server that receives your documents — turn off Wi-Fi after the page loads and it still works.
  • No account. Free comparisons need no signup. Paid features use a license key, not a login.
  • Structure-aware. Word documents compare as documents (redlines, tables, formatting), spreadsheets as cells, JSON/YAML/XML by meaning rather than by line — so formatting noise doesn't drown the real change.

Who is it for?

People who need to know what changed between two versions of a file and don't want that file leaving their machine: professionals reviewing contract drafts, analysts checking workbook revisions, developers and ops engineers diffing configs, and anyone cleaning up a photo library. If your review workflow needs document editing, merging, or accept/reject of individual changes, Diffesq is not that tool — it compares and reports, it never modifies your documents.

What does it cost?

Text and Markdown comparison is free and unlimited. Diffesq Pro — full structured-file comparisons and unwatermarked exports — is $2.97/month, $27.99/year, or $49 once for a lifetime license. See Pricing for details.

Learn more