See exactly what changed on a website between two scans
BYDIFF finds changes in pages, SEO, content and technical website state and shows exactly what changed between scans. Detailed technical data remains available inside the report.
After the trial, choose PRO: $98/month, $940/year, or $1,900 lifetime. Activation is manual via email or Telegram. After 1,000 URLs Scanner Agent asks for confirmation before continuing a large scan.
Configurable retention plus protected ★ checkpoints.
Appearance, content and metadata; desktop, tablet and phone.
What does DIFF mean?
The BYDIFF name reflects the product’s core mechanism: comparing two website states.
DIFF is short for Difference. BYDIFF saves website states during scans, compares them, and shows what was added, removed, or changed. Recognized dynamic values such as view counters, dates, time, nonces and tokens do not count as meaningful changes by themselves.
Why BYDIFF is useful
Four practical workflows based on factual website changes.
Verify which pages, product cards, copy, prices, images and SEO elements actually changed between scans.
Compare SEO, developer and agency reports with the website's actual state.
Spot discovered new pages, categories, products, copy, images, links, public prices and SEO fields.
Catch 404/410, 5xx, missing URLs, unexpected metadata changes and other problems after releases and updates.
What the extension tracks
It is not limited to Title and copy. BYDIFF compares multiple page layers.
A comparison you can verify visually
Choose two saved versions of the same URL and inspect differences by layer.
Description: English
H1: English
Description: English
H1: English
Split mode shows both copies at the same time with synchronized scrolling. Visual archive presets include desktop 1440×900, tablet 768×1024 and phone 390×844. Archived JavaScript is not executed.
Automatic monitoring
Checks can run manually or on a schedule while Chrome is open.
The background queue avoids scanning multiple websites simultaneously and supports pauses between projects.
Changes, scan problems, HTTP 5xx, successful no-change scans and local-folder reminders.
Gentle, Balanced or Fast. BYDIFF automatically slows down on heavy pages and 429/503 responses.
State, queue, speed, retries, 429/503, current URL, stall time and safety caps.
Less dynamic noise
For dates, counters, online chats and other constantly changing blocks you can create CSS exclusions or URL masks. An exclusion does not modify the website or delete the archive; the matching change simply stops being treated as significant. Recognized view counters, typical dates and time, UUIDs, nonces, tokens and other dynamic values are also filtered from the change log.
Your first comparison in 4 steps
Enter the domain and optionally give the project a custom name.
HTML+CSS copies, images and visual history are stored in the BYDIFF data directory.
The first successful scan becomes the baseline.
The second successful scan already shows real changes.