Privacy policy
Effective 18 August 2026 · applies to the MurmPulse browser extension, published by MurmTools.
MurmPulse transmits nothing. It stores your readings on your own machine, because comparing them is the entire product, and there is nowhere for them to go — no server, no account, no analytics, and no network code of any kind in the package.
What the extension does
When you click the MurmPulse icon on a page, it reads what that page publishes about itself — a price, a sold count, a review total, a rating — and records one reading with a timestamp. On a later visit it reads again and reports the difference: which way the figure moved, at what rate per day, and how many readings that rests on. Everything is produced and displayed on your machine.
Permissions
| Permission | Why it exists |
|---|---|
activeTab |
Grants temporary access to the single tab you clicked the icon on, and only at that moment. It is used to read the figures already published on that page. The access ends with the tab. |
scripting |
Runs one read-only function, once, in that tab. The function is bundled in the extension. It does not modify the page, attach listeners, or persist after returning its result. |
storage |
Keeps the readings. This is the product: without a previous reading there is no change
to report. It is chrome.storage.local, which never leaves the device and is
not synced to any account. |
There are no host permissions. MurmPulse has no access to any website until you click its icon on that website. It cannot run in the background, and it never touches another tab.
Data we collect
None. Collection means transferring data off your device. MurmPulse has no code path
that sends anything anywhere: no fetch, no XMLHttpRequest, no
WebSocket, no sendBeacon. The only URL in the package is a link to
murmtools.com in the panel footer, which does nothing until you click it.
Data we store
On your machine, and only there. One entry per page you have taken a reading on,
holding a list of {timestamp, value} pairs and the page's title and address.
It is bounded by construction rather than by anyone remembering to prune: full resolution for 30 days, one reading per day out to a year, one per week beyond that, a hard cap per page, and a 5 MB budget past which new pages are not recorded — and the panel says so rather than silently stopping. When older readings are dropped to stay inside that budget, the panel says that too.
Uninstalling the extension removes all of it. There is no copy anywhere else.
Third parties
There are none. No analytics, no error reporting, no A/B testing, no advertising, no payment processor — MurmPulse is free and has no paid tier.
Even the typefaces are bundled inside the extension rather than fetched from a font host. A tool whose argument is that your readings stay with you should not quietly make a request on every open.
What MurmPulse will not tell you
It does not forecast. A trend it reports is a record of the change between readings you took; it is not a projection, and there is no field in the code for one. Where a figure cannot be known — a percentage from a baseline of zero, or a page that states “500+” rather than a count — it prints an em-dash and the reason instead of an estimate.
Children
MurmPulse is a research tool for people evaluating products to sell. It is not directed at children and collects no data from anyone, of any age.
Changes
If this policy ever changes, the effective date above changes with it. Since the extension collects nothing, any change would be a narrowing rather than a broadening — and if that ever stopped being true, it would be stated here before it shipped.
Contact
Questions about this policy: [email protected].