How to Compare Two Versions of a Web Page and See Exactly What Changed

Pages change silently. A privacy policy gains a clause, a product loses a feature, a pricing table shifts by a dollar, a news article is corrected without a note. If you need to know *exactly* what changed — and prove it — eyeballing two tabs is not enough. You need the two versions, a way to line them up, and a record of what you found.

This guide shows four ways to compare versions of a web page, from free and manual to fully automated.

First, get the two versions

Every comparison starts with two captures: A (before) and B (after). Usually B is the current live page or the newest capture, and A is a capture from around the date you care about. Find them in the Wayback Machine calendar, or use Snapshot by date to jump to the capture closest to a specific day in every archive.

Method 1: Side by side (free)

Open both captures in two windows, snap them left and right, and scroll together. This is quick for layout changes and obvious edits, and it needs nothing installed. In Web Archive Viewer, the free Compare versions tool lets you pick A and B from the Timeline, a date, or quick picks such as “1 year ago”, and opens them side by side for you.

The limit is your attention: a changed number in paragraph nine or a removed sentence in a long policy is easy to miss.

Method 2: A text diff

A diff lines up the text of both versions and highlights what was added and removed, the way code review tools do. You can make one by hand: copy the readable text of each capture into two files and run a diff tool.

# Save each capture's text, then compare line by line
curl -s "https://web.archive.org/web/2021id_/https://example.com/terms" | lynx -dump -stdin > a.txt
curl -s "https://web.archive.org/web/2026id_/https://example.com/terms" | lynx -dump -stdin > b.txt
diff -u a.txt b.txt

This works, but it's fiddly: boilerplate, navigation and cookie banners show up as changes, and line breaks shift whenever a sentence is edited. A diff built for web pages strips the chrome first and compares the readable text.

Method 3: A diff built for web pages

Web Archive Viewer Pro's Compare does the extraction and the diff for you and adds what you'd otherwise have to work out by hand:

The change summary is the part people use most. “82% unchanged, 3 headings added, price $49 → $59” tells you in one line whether a page is worth reading closely.

Method 4: Visual compare

Some changes aren't in the text at all: a redesigned checkout, a moved disclaimer, a swapped hero image. Visual compare renders both captures at 1280 px and gives you three views — side by side, an overlay with an opacity slider, and a pixel difference that highlights every changed pixel, with a strip showing where on the page the changes are and the percentage of pixels changed. You can download both screenshots for your records.

Turn the comparison into evidence

If you need to show someone else what changed — a client, an editor, a lawyer, a manager — send them something they can check. An evidence report turns a Compare result into a shareable page on webinternetarchive.com with the two captures and their archive links, the change summary, the metadata, the links and text excerpts, ready to print or save as PDF. Because every claim links back to a timestamped capture in a public archive, anyone can verify it independently.

If you're writing it up yourself, cite both captures with their full archive URLs. Our guide on citing archived web pages has ready-made formats for APA, MLA, Chicago and Wikipedia.

Common things people compare

• Terms of service and privacy policies — what rights were added, which retention periods changed.
• Pricing pages — plan limits, prices and which features moved between tiers.
• Product pages — specifications, claims and availability.
• News articles — silent corrections and headline changes.
• Competitor homepages — positioning, messaging and calls to action over time.
• Your own site after a migration — missing content, broken headings and lost internal links.

For a page that changes often, comparing two versions is only half the picture. Historical SEO analysis tracks titles, headings, word counts and prices across up to twelve captures at once and charts the trend.

FAQ