Introducing modsignal
Describe what you care about in plain language. modsignal checks the page and alerts you only when it truly changes, with evidence attached.
Most page monitoring tools answer the wrong question. They tell you whether a page changed — a class name, a rotating testimonial, a cookie banner — and leave you to figure out whether the change matters. After the third false alarm, you stop reading the alerts. After the tenth, you turn them off. The one change you actually cared about arrives in an inbox you've already learned to ignore.
modsignal starts from the other end: you describe the change you care about, in plain language.
Watch this pricing page and tell me if the per-seat price or a plan limit changes. Ignore copy edits.
Alert me if this vendor adds a subprocessor outside the EU.
Tell me when this changelog announces a breaking API change.
We check the page on the schedule you set, compare what we find against the last version we saw, and only alert you when the thing you described actually happened.
One sentence, with evidence
When something changes, you don't get a screenshot diff to eyeball or a wall of highlighted HTML. You get one sentence:
Linear removed the 14-day free trial from its Business plan. New since July 19.
Attached to that sentence: the before, the after, and a confidence score. You can forward the alert to your pricing lead without re-checking the page yourself — the evidence is already in it.
Three check tiers
Not every page needs the same machinery, so every monitor picks one of three tiers:
- Exact diff — a byte-for-byte text comparison. Cheap, fast, and right for pages where any change is worth knowing about: a legal document, a subprocessor list, a spec.
- Semantic (AI) — reads the new page against your prompt and decides whether the change you described actually happened. This is the tier that ignores the rotating testimonial and catches the quiet trial-length change.
- Browser agent — renders JavaScript-heavy pages in a real browser first, then checks them the way a person would. For dashboards, pricing calculators, and anything that's an empty shell without JS.
You can start a monitor on exact diff to learn a page's rhythm, then move it to semantic once you know which changes are noise.
Who it's for
The people we built modsignal for have one thing in common: they set a monitor once and only come back when an alert fires.
- Product teams watching competitor pricing and API deprecation notices.
- Security and compliance people watching subprocessor lists, DPAs, and terms of service.
- App vendors watching marketplace listings and reviews.
- Agencies watching tender and grant portals.
For each of these we ship a watch pack — a template with prompts that already work, so the first monitor takes a minute, not an afternoon.
Start free
The free plan gives you 3 monitors with daily checks on the exact-diff and semantic tiers, no credit card required. Paid plans buy reach — more pages, faster checks, more teammates — never per-alert pricing, because a tool like this only works if you never hesitate to let it check.
Set the first monitor up in a minute at app.modsignal.io. Then close the tab. We'll tell you when it changes.