How often can ProofSnap check a page?

As often as every 5 minutes on Developer, Startup, Growth, Solo and Company. Website Archive checks each page once a day. The cadence list offers every 5, 15 or 30 minutes, hourly, every 6 hours, daily and weekly, and a cron expression lets you set your own times.

Do checks that find no change cost anything?

No. In On change (monitor) mode, a check that finds no change makes no package and is not billed. Only full captures count toward your monthly capture quota: the first one, one after each change, and the ones the Full capture option adds.

What counts as a change?

A change in the text of the page source the server sends. Before it compares, the check ignores date-times written in ISO format, numbers of six or more digits, spacing and letter case, so an ISO-format timestamp or a long session number does not start a capture. Text that the page loads with JavaScript is not part of the check. A blank or near-empty page or an error page does not count as a change either.

Does a monitor catch a changed image?

No. The check compares text only, so a new product photo, a new logo or a layout change with the same text does not start a capture. For pages where the images matter, use Fixed interval or Cron expression, which make a full capture with a screenshot at every run.

How precisely is the change dated?

The package records when its capture was taken. The change itself happened between the last check that found the page unchanged and that capture, so the interval you choose sets the precision: with a check every hour, the change is dated to within that hour.

What happens when I reach my monthly limit?

Captures beyond those included in your plan keep running and are billed as overage. When your monthly maximum is reached, the run is skipped and the automated capture stays active. The list shows why, for example "last run skipped, monthly limit reached", and the next run goes ahead once the limit allows. If the page text still differs at the next run that goes ahead, that run captures it.

How am I told that a page changed?

Through a webhook. In the Webhooks section, subscribe an HTTPS endpoint to the Page change detected event. Each delivery names the automated capture, the captures before and after the change, and the result of ProofSnap's comparison of the two.

Can I monitor a page behind a login?

No. The dashboard captures pages from ProofSnap's servers, so it can only reach public pages. For a page behind a login or a paywall, capture it with the ProofSnap browser extension, which records what your own browser shows.

Can I create monitors through the API on Website Archive?

No. On Website Archive, API keys are read-only: with them you can list, download and verify captures, and webhooks still deliver events. You start new captures and automated captures in the dashboard.

Step-by-step guide

Monitor web page changes as evidence

To monitor web page changes as evidence in 2026, set up an automated capture in the ProofSnap Dashboard in On change (monitor) mode. ProofSnap checks the text the server sends as often as every 5 minutes, saves a sealed, dated evidence package whenever a check finds the text has changed, and can send you an alert each time.

Use it to watch a competitor's claims, an infringing listing, a set of terms and conditions, a defamatory post or a price. The dashboard screens below are redrawn from the actual interface.

By Radim Motycka, Founder and Lead Engineer at ProofSnap, who built the dashboard, the API and the capture pipeline this guide walks through. · Last updated: October 21, 2026

Checks as often as

Every 5 minutes

A sealed package

When the text changes

Checks with no change

Not billed

The ProofSnap Dashboard at app.getproofsnap.com with the plan card and a new batch capture, next to the matching API request and its 202 response

The ProofSnap Dashboard with a new capture, next to the same capture started through the API.

Before you start

A ProofSnap Dashboard account on a paid plan. New to the dashboard? Start with Getting started with the dashboard.
The address of a public page. Pages behind a login need the ProofSnap browser extension.
For alerts: an HTTPS endpoint that can receive webhooks.

Step 1

Check what your plan allows

You set up monitoring in Automated captures, its own section of the dashboard. How many pages you can watch at once depends on your plan. Only active automated captures count: a paused one frees its slot. Sandbox mode (before you choose a plan) allows none. Plans and prices are in Choose a plan.

Plan	Active at once	Most often
Developer, Solo, Company	3	Every 5 minutes
Startup	25	Every 5 minutes
Growth	200	Every 5 minutes
Website Archive	30	Once a day

1Plan details. On the plan card, Plan details lists Automated captures with your limit.
2Counter. Next to the section title: how many of your slots are in use. When they are full, + New explains the limit instead of opening the form.
3Included captures and monthly maximum. Automated captures draw on the same monthly capture quota as everything else. Each capture beyond your plan's included captures is billed as overage. When your monthly maximum is reached, runs are skipped until the limit allows them again (step 6).

PlanStartup

Plan details

Automated capturesUp to 25 active

Automated captures 2 / 25 active2

+ New

3 Automated captures count toward your monthly quota. Once you pass your included allowance, each further capture is billed as overage.

The plan details row and the section header, simplified, on the Startup plan. The counter is an example.

Step 2

Create an automated capture

In Automated captures, click + New and paste the address of the page you want to watch. Then choose how it runs. To keep a record each time a check finds that the page text has changed, choose On change (monitor); an automated capture in On change (monitor) mode is called a monitor below. The check reads the text in the page source the server sends. For pages that load their content with JavaScript, such as many single-page apps, social posts and some listings, choose Fixed interval or Cron expression instead. Click Create when you are done; the new entry appears in the list above the form.

1Mode. Fixed interval makes a full capture at every run. On change (monitor) checks the page at every run and captures it when its text has changed. Cron expression runs at times you set (for example 0 9 * * 1, Mondays at 9:00), with an optional Time zone that defaults to UTC.
2Cadence. Every 5, 15 or 30 minutes, hourly, every 6 hours, daily or weekly. In On change (monitor) mode it sets how often the page is checked.
3Full capture. Only when the page changes, or At least every 30, 90, 180 or 365 days. With the second option, a full capture is also taken when the newest one is older than that, even if nothing changed. Useful when you need a fresh dated copy on file at regular intervals.
4Alert. On any change, or Only on text changes. With the second option, no alert is sent when the comparison with the previous capture finds no change in the visible text. Step 5 sets up where alerts go.
5Case / matter reference and eIDAS. The reference goes into every package. The eIDAS checkbox adds to each full capture a qualified electronic timestamp under the eIDAS Regulation, issued by Disig a.s., a Qualified Trust Service Provider on the EU Trusted List, at $1.99 per timestamp.
6Capture options. The same options as for a single capture: the evidence PDF language, full-page scroll, consent banner and popup dismissal, the network log (HAR) and more. In On change (monitor) mode they apply to the full capture taken when a change is detected.

Automated captures

https://competitor.example.com/pricing

Mode

On change (monitor)

Cadence

Hourly

Captures run only when the page changes, so the number depends on the page. Your monthly maximum is 4,000 captures.

Full capture

At least every 90 days

Alert

Only on text changes

Case / matter reference

Acme v. Rival, 2026-0457

Add qualified electronic timestamp (eIDAS)

Billed extra on your plan: $1.99 per eIDAS stamp.

6Capture options

Monitoring runs a lightweight probe each cycle; capture options apply to the full capture taken when a change is detected.

CancelCreate

The form in On change (monitor) mode on the Startup plan, simplified. The address, the reference and the monthly maximum are examples.

Step 3

Read the cost estimate

Before you click Create, a line below the cadence (or the cron expression) says how often the schedule will run in a month and what it adds to your bill. It updates as you change the cadence or check the eIDAS box. The estimate assumes a 30-day month and is capped at your monthly maximum, the number of captures after which ProofSnap stops capturing for the month.

1Within your plan. Daily on Startup is about 30 runs, within the 200 included captures, so the line shows only the number.
2Beyond your plan. Hourly on Startup is about 720 captures, 520 of them beyond the 200 included, at $0.60 each. With eIDAS checked, every run adds $1.99 as well.
3On change (monitor). How many captures run depends on how often the page changes, so the line shows your monthly maximum instead of a price.
4Too frequent. For a cron expression that runs more often than your plan allows, the line says so instead of showing a price, and ProofSnap does not create the schedule. Cadences that are too fast for your plan cannot be picked.

Cadence

Daily

This schedule runs about 30 times a month.

Cadence

Hourly

Estimated extra cost: about $312 / month. About 720 captures a month: $312 for the captures beyond the 200 included.

Mode

On change (monitor)

Captures run only when the page changes, so the number depends on the page. Your monthly maximum is 4,000 captures.

Cron expression

* * * * *

Too frequent: your plan allows automated captures at most once every 5 minutes.

The estimate line in four situations, on the Startup plan without eIDAS. The figures follow from the plan's prices and are examples for that plan.

Step 4

Know what each run produces

A Fixed interval or Cron expression schedule makes a full capture at every run, changed or not. That is the right choice when you need a copy at set times. On change (monitor) is built for tracking changes over time: it keeps a record of each detected version without filling your history with identical copies.

1First run. A full capture: the starting version that later changes are compared against. It is made once a check finds readable text in the page source; for a page whose text is loaded by JavaScript, use a Fixed interval or a Cron expression.
2No change. Each cycle runs a lightweight check of the text in the page source the server sends. When the text is the same, no package is made and nothing is billed.
3Text changed. A full capture with the capture options you set. ProofSnap then compares it with the previous capture and sends the result with the alert (step 5).
4A copy is due. With Full capture set to at least every N days, a full capture is also taken when the newest one is older than that.

Every full capture is a complete evidence package: screenshot, page HTML and text, evidence PDF, SHA-256 hashes, an RSA-signed manifest submitted to OpenTimestamps (Bitcoin), and the eIDAS timestamp if you selected it. See How to verify an evidence package.

On change (monitor), run by run

1Oct 1, 09:00Sealed package
First version on record.
2Oct 1, 10:00 to Oct 14, 15:00
Hourly checks, text unchanged: no package.
3Oct 14, 16:00Sealed package
Text changed: full capture, comparison, alert.
Oct 14, 17:00 onward
Hourly checks against the new version.
490 days after the last captureSealed package
No change, but a copy is due.

A diagram, not a dashboard screen: an hourly monitor with Full capture set to at least every 90 days. The dates are examples.

Step 5

Get an alert when the page changes

Alerts are delivered as webhooks to an endpoint you control, such as an automation tool or your own system. Open Webhooks and click + New webhook. Each delivery is signed, and the signing secret is shown only once, right after you create the webhook: copy it then.

1Endpoint URL (https). The public HTTPS address that receives the events.
2Events. Page change detected fires after the full capture that records a change, with the captures before and after the change and the comparison results for text, images and metadata. Automated capture paused tells you when ProofSnap pauses one (step 6).
3Filter (optional). One automated capture limits the webhook to one page you watch; One website (host) to one site.
4Create webhook. Saves it. The list shows each webhook's last delivery.

Webhooks

+ New webhook

Endpoint URL (https)

https://hooks.example.com/proofsnap

Events

Capture completed Page change detected Automated capture paused Capture failed

Filter (optional)

One automated capture

Automated captures

competitor.example.com/pricing

Cancel4Create webhook

The new webhook form, simplified: the real form lists more events and has an optional description. The endpoint and the page are examples.

Step 6

Watch the status of your automated captures

The list under Automated captures shows every page you watch. Edit opens the form with its settings, Pause and Resume stop and restart it, and Delete removes it (the captures it already made stay in Capture history).

1Cadence. How it runs and how many captures it has made so far. An automated capture in On change (monitor) mode also shows its Alert setting.
2Skipped run. An active automated capture whose last run hit a limit stays active and runs again by itself. The note says which: monthly limit reached, company monthly limit reached, too many captures running at once or daily test capture limit reached.
3Paused, with the reason. ProofSnap pauses an automated capture and shows one of these reasons: failed 5 times in a row, invalid schedule, no active billing or, after a plan change, not included in your plan. Reaching your monthly maximum does not pause it: the run is skipped instead (callout 2). Fix the cause, then click Resume.
4Next run. When the next check or capture is due.

Automated captures

2 / 25 active

+ New

Source	Cadence1	Next run4	Status
https://competitor.example.com/pricing eIDAS · Acme v. Rival, 2026-0457	On change (monitor) · 4× Alert: Only on text changes	10/21/2026, 4:00 PM	● Active	EditPauseDelete
https://shop.example.com/listing/4821	Hourly · 212×	10/21/2026, 4:00 PM	● Active (last run skipped, monthly limit reached)2	EditPauseDelete
https://example.org/terms	Daily · 9×	-	Paused (failed 5 times in a row)3	EditResumeDelete

The Automated captures list, simplified. The pages, counts, dates and statuses are examples.

Step 7

See the timeline in Capture history

Every full capture a monitor makes lands in Capture history, next to your other captures. To see one page's versions in order, filter the list by its automated capture. Download any version as its own evidence ZIP.

1Filters. Under Automated capture, pick the page. You can narrow it further by date.
2Server filter. A line above the list names the filter, and Clear the server filter shows everything again.
3Automated. The type column marks each capture the monitor made, next to the device it was captured on.

Capture history

1Filters

Automated capture

competitor.example.com/pricing · On change (monitor)

2Filtered on the server: automated capture https://competitor.example.com/pricing

Oct 14, 2026, 4:01 PM
Desktop · Automated3
Completed
Oct 6, 2026, 11:02 AM
Desktop · Automated
Completed
Oct 1, 2026, 9:01 AM
Desktop · Automated
Completed

Capture history filtered by one automated capture, simplified: the real list is a table with more columns and row actions. The dates are examples.

Step 8

Compare two captures

To show what changed between two versions, open Tools, then Compare captures. Choose the earlier capture as Before and the later one as After, and click Compare. The comparison is sealed as its own evidence package, with a report of the text, images and metadata that changed, and appears in Capture history with the type Compare. It counts as one capture toward your monthly usage.

1Before and After. Both captures must be completed web page captures. Swap reverses the order. Captures taken on a different device or with different settings get a warning, because the text and layout can differ even when the content has not changed.
2Comparison report. The evidence PDF language and an optional eIDAS timestamp, as for a capture.
3Result. A one-sentence summary first, then the images, text and metadata that changed. The share of changed text and the lines added and removed are counted line by line.
4What changed on the page. The removed and added text, each with how far down the page it appears.

Compare captures

Before

competitor.example.com/pricing · Oct 6

Swap

After

competitor.example.com/pricing · Oct 14

Comparison report

English

Counts as one capture.Compare

The page content changed.

Images changed

0 from the page's site

Text

2.4% changed

Lines: +1 / −1

Metadata

What changed on the page

≈% shows how far down the page a change is (0% = top, 100% = bottom).

Removed

Starter plan: $19 per month

≈12%

Added

Starter plan: $24 per month

≈12%

The Compare captures tool with a result, simplified. The pages, dates and changes are examples.

Step 9

Place a legal hold on key captures

When a version becomes important, for example the capture that shows the infringing listing or the post before it was edited, keep it from being deleted. Open the capture in Capture history and click Place legal hold. Legal hold is available on paid plans, for live (non-test) captures only. Holds are released when your subscription ends, unless you stay on a plan that retains your data.

1What it does. While the hold is in place and your account stays on a plan that retains your data, the capture cannot be deleted, either manually or automatically when its retention period ends.
2Reason (optional). A short note on why, kept with the hold.
3Place legal hold. Confirms it. The capture then carries the Legal hold badge, and a comparison made from it is held with it.

To hold several captures at once, select them in Capture history and use the bulk action, or place a hold on every capture from one domain. For a whole case, group the captures in a matter: see How to organize web evidence in matters. Need to share a capture without personal data? See How to redact a web capture.

Place legal hold

1A capture under legal hold cannot be deleted, either manually or automatically when its retention period ends.

Reason (optional)

Price change, Acme v. Rival

Cancel3Place legal hold

The legal hold dialog, simplified. The reason is an example.

Step 10, for developers

Automate monitors with the API

Watching many pages, or pages your own system finds? On an API plan, the steps above are also available through the ProofSnap API with an API key from Developers. On Website Archive, API keys are read-only, so create automated captures in the dashboard. The API documentation describes every field and error.

POST /v1/scheduled-captures creates a monitor: mode interval, cron or on_change, interval_seconds, max_capture_age_seconds, alert_on and an optional webhook_url.
GET, PATCH and DELETE /v1/scheduled-captures/{schedule_id} read, change, pause or remove it; GET /v1/scheduled-captures/{schedule_id}/runs lists its 50 newest captures.
POST /v1/webhook-subscriptions subscribes an endpoint to monitor.change_detected and schedule.paused.
POST /v1/compare compares two captures; POST /v1/legal-holds places or releases holds in bulk, for example on every capture of one schedule.

Create a monitor

curl -X POST "https://api.getproofsnap.com/v1/scheduled-captures" \
  -H "Authorization: Bearer ps_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://competitor.example.com/pricing",
    "mode": "on_change",
    "interval_seconds": 3600,
    "max_capture_age_seconds": 7776000,
    "alert_on": "text"
  }'

7776000 seconds is 90 days.

A request in the form the API documentation describes. The key and the page are placeholders.

Common questions

Keeping your own website on record instead? See How to archive your website for regulators.

Start watching a page

Open the dashboard, go to Automated captures and click + New to put your first page on record.

Open the ProofSnap Dashboard

More: Getting started with the dashboard · API documentation · How to verify an evidence package