How can we help?

Drop the first version on the start page, or choose it, then choose the other version. You can also choose both at once. PowerLensopens them side by side with every change marked.

The documents walkthrough shows the rest.

Documents (Word, Google Docs, PDF, OpenDocument, RTF, EPUB, web pages, Markdown, CSV and TSV, and text and code files), pictures (PNG, JPEG, GIF, WebP, SVG, BMP) and recordings (MP3, WAV, M4A/AAC, Ogg/Opus, FLAC, WebM). Choose what you are comparing first; the pickers then offer those files.

Yes. Any two documents can be compared, whatever their formats. The start page asks for two files of the same kind (documents, spreadsheets, images or recordings), and in the workspace you can replace either side with any file. The Word against PDF sample shows how it looks.

No. There is no account and nothing to sign in to. PowerLens runs in your browser tab.

Each comparison is saved as you work, where you chose when you started it: in this browser, or on the server, either as a record (its name, what the files were, your review, notes and transcripts) or with its two files too. They are all listed in your comparisons, where you can open, rename, move or delete them.

One kept as a record opens straight away in the browser that saved it; anywhere else, it asks for the two files and checks they are the same ones. A comparison you didn’t save as you started it (a sample, say) is saved with Save beside the name at the top.

Yes. Install it with your browser’s Install button and it keeps working without a connection once opened. Saving a PDF and transcribing audio need to download their tools the first time.

Red words are only in A, green words only in B. A blue bar marks a changed paragraph, and a hatched block marks a paragraph only one side has. Formatting-only changes are flagged on their own.

Use the arrows between the columns for a whole paragraph, click a marked word for just that edit, or press Alt+→ or Alt+← for the current change. Copy changes › Make B match A copies everything. All of it can be undone.

Yes. Compare options can ignore formatting, letter case, extra spaces, empty paragraphs, and curly versus straight quotes and dashes.

When a paragraph moved and its text is the same or nearly the same, PowerLens shows it as moved, with a link to where it went, instead of as removed in one place and added in another.

No, only the document body. Headers, footers and comments stay in the file when you export. Tracked changes are compared as if they were all accepted, and are kept as they are.

Yes. A document loaded from Word or OpenDocument is saved from the original file, with only the paragraphs you copied changed. Styles, headers, footers and page setup stay.

Either Export › Download Word document and upload it in Google Docs with File › Open › Upload, or Export › Copy formatted text and paste over the original.

A Word file of B with every change from A as a tracked change, and your notes as Word comments. Accept them all in Word to get B, reject them all to get A. It can be a PDF instead.

Share saves both documents and the whole review in one .powerlens file, optionally locked with a password. Whoever opens it in PowerLens carries on where you left off.

The PDF is probably a scan: pictures of pages, with no text inside. Run it through OCR (most scanner apps and Adobe Acrobat can), or compare the original document instead.

PowerLens can’t read those. Open the file in the app it came from, remove the protection if you are allowed to, and save a copy.

They aren’t read. Save them as Word or PDF first. For spreadsheets, save each sheet as CSV to compare it row by row.

The PDF maker is downloaded the first time a PDF is saved, so that first time needs a connection. After that it is kept by the browser. Only the tool is downloaded; your document never leaves.

The comparison in each tab is kept in this browser only: clearing site data, using a private window or switching browser starts afresh. Comparisons you saved are in your comparisons, unless the site data was cleared; those kept on the server need the same browser (its cookie) to be found. See cookies and storage.