One-line summaries
- Visualping: the polished, marketing-friendly cloud monitor with great visual diffs. Built for non-technical buyers watching competitor pages.
- Distill.io: the original browser-extension monitor with a paid cloud tier on top. Best when you want a local-first watchlist of a handful of pages.
- OnChange: the cloud-first product built for engineering and agency teams. Sub-minute checks, API monitoring, WCAG scans, AI summaries, and a clean REST API on every plan.
Side-by-side feature matrix
| Feature | OnChange | Visualping | Distill.io |
|---|---|---|---|
| Free plan | |||
| Runs in the cloud (no browser needed) | |||
| Sub-minute check intervals | |||
| Visual (screenshot) diffs | |||
| Text and content diffs | |||
| CSS selector + XPath targeting | |||
| API / JSON endpoint monitoring | |||
| AI change summaries on every alert | |||
| Git commit attribution | |||
| WCAG accessibility scans | |||
| Slack / Discord on free plan | |||
| Custom webhooks | |||
| REST API for monitor lifecycle | |||
| Self-serve transparent pricing |
Yes, Partial, No. Based on publicly available information as of May 2026.
Where each tool wins
Visualping wins on consumer polish
Visualping has spent more than a decade refining its UX for non-technical buyers. The Chrome extension, the email digests, and the visual diff viewer feel native to a marketing workflow. If your buyer is a brand manager or PR lead, this is the lowest-friction tool to deploy. It also has the most recognizable brand in the category, which matters when you're getting purchase approval.
Distill.io wins on local-first control
For a single user with a personal watchlist, Distill's extension is genuinely excellent. Everything runs locally; no account required; data never leaves your machine. The cloud tier exists for when you want monitoring without a laptop, but at that point you're comparing against full cloud-native products and the gap widens.
OnChange wins on speed and depth
OnChange is built for teams that need detection in seconds, not minutes, and that monitor more than just pages. The four differentiators in practice:
- -Sub-minute intervals. 60s on Pro, 30s on Business, 10s on Enterprise. Visualping typically caps at 5 minutes on entry tiers.
- -API / JSON monitoring. Dedicated diff UI with JSONPath targeting. Visualping doesn't ship this; Distill supports it but in a more limited form.
- -Commit attribution. Every detected change is matched against your repo's recent commits. Unique to OnChange across all three tools.
- -WCAG accessibility scans. Full axe-core scans with attested baselines. Useful for agencies and any team with compliance obligations.
Pricing snapshot
All three publish their pricing, which is a good sign. The shape of the deal is what matters.
Visualping starts around $14/month for a few monitors with hourly checks; faster intervals and additional channels live on higher tiers. Solid value for visual-only marketing use cases.
Distill.io extension is free; Web Edition (cloud) starts around $15/month and scales with monitor count. If you'll use the extension exclusively, it's effectively free.
OnChange Free is $0 with 5 monitors at 30-min intervals and every feature (Slack, Discord, webhooks, API, visual diffs, AI summaries, WCAG scans). Pro is $12/month for 50 monitors at 60s; Business is $39/month for 300 monitors at 30s. Every feature is available on every plan; you pay for monitor count and frequency.
Alert quality, in practice
One thing you can't tell from a feature matrix: what the alerts actually look like when they land in Slack. The three tools take different approaches.
Visualping sends a tidy email or Slack message with the before/after screenshots and highlighted regions. It's visually polished but text-light: you'll usually click through to understand what happened.
Distill's alerts vary by channel; the extension's in-browser badge is great for the local workflow, and the cloud tier sends compact text-first notifications.
OnChange includes an AI change summary on every alert that describes the change in plain English ("the price increased from $49 to $59 on the Pro plan; the 'Try free' CTA changed color from blue to green") alongside the diff and screenshot. For mobile triage and on-call workflows, this is the single biggest practical difference between the three.
Which one should you pick?
A decision tree, in order:
- Are you a single user with a personal watchlist? Distill.io extension is free and excellent.
- Is the primary buyer non-technical and the use case visual-only? Visualping. Polished, well-known, and the alert UX matches the workflow.
- Do you need sub-minute checks, API monitoring, or accessibility scans? OnChange. None of the other two ships all three.
- Are you an engineering team that ships code? OnChange. The commit attribution feature alone pays for itself the first time a deploy causes a regression you didn't catch.
For a deeper buying framework that's not specific to these three tools, see How to choose a change detection tool: 10 things that matter. For the full eight-tool comparison, see Best change detection software in 2026.