Online Tool Store
SSL Expiry Monitor
Log domains and their SSL certificate expiry dates to see a sorted countdown of which certificates need renewing soonest, stored only in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Stored only in this browser's local storage — nothing is sent to a server, and clearing your browser data clears this list.
How SSL Expiry Monitor works
- A sample list of three domains at different points in their renewal window loads automatically the first time you open the tool.
- Add your own domain and its certificate's expiry date (from your certificate authority or hosting dashboard) with the Add button.
- Every certificate is sorted by days remaining, soonest first, and colour-coded: green when healthy, amber inside 30 days, red inside 14 days or already expired.
- The full list is saved to this browser's localStorage automatically, so it's still there the next time you open the page — no account or server involved.
Days remaining is a straightforward date subtraction — expiry date minus today, in whole days — but seeing every certificate ranked together, instead of hunting through separate CA dashboards, is what actually catches a renewal before it lapses.
FAQ
Why do I have to enter expiry dates manually instead of it checking automatically?
A page running in your browser has no way to open a TLS connection to an arbitrary domain and read its certificate — that would require a server-side check, which conflicts with this tool never sending your list of domains anywhere. Manual entry keeps the whole list private, at the cost of needing to note the date yourself (most certificate authorities email it to you already).
Where is my certificate list stored?
In this browser's localStorage, under a key scoped to this tool — nothing is transmitted anywhere. It persists across visits on this device and browser, but clearing your browser data, using a different browser, or private/incognito mode will not show the same list.
What do the "Renew soon" and "Renew now" thresholds mean?
A certificate within 30 days of expiry is flagged amber ("Renew soon") and within 14 days is flagged red ("Renew now") — commonly used lead times that give enough buffer to renew before a site starts throwing browser security warnings.
How we compare
| Feature | Online Tool Store | Doing it manually | A generic online tool |
|---|---|---|---|
| No file upload — runs in your browser | ✓ | N/A | ✗ |
| No sign-up required | ✓ | ✓ | ✗ |
| Free, no watermark | ✓ | ✓ | ✗ |
A full uptime-monitoring service that checks certificates automatically means handing over your domain list and usually a monthly fee. This tool skips both — you enter dates once, the sorted countdown lives in your browser's local storage, and nothing about your infrastructure is sent anywhere.