Bulk SSL Checker
Check SSL certificates for a list of hostnames at once.
Fetch the leaf certificate for many hosts at once and compare expiry, issuer and chain.
Hostnames are checked on our server, then discarded — results are never cached or shared.
Quick answer
Bulk SSL Checker inspects the certificates of many hostnames at once and returns a table of issuer, expiry, days remaining, and chain health, so you can monitor a whole fleet in one pass. It exists to catch certificates before they expire, the top cause of self-inflicted TLS outages.
Bulk SSL Checker inspects the TLS certificates of many hostnames at once, so you can monitor an entire fleet of sites and services in a single pass instead of checking each one by hand. You paste a list of hostnames and get a table of what matters most for operations: who issued each certificate, when it expires, how many days remain, and whether the chain is healthy. It is built for the recurring, unglamorous job of making sure nothing is about to lapse.
Expiry is the number one cause of self-inflicted TLS outages, and it always hits at the worst time, taking a whole service down for every user at once. The more certificates you run, across web servers, APIs, mail hosts, and load balancers, the easier it is for one to slip through. Checking them in bulk turns a scattered risk into a single sortable list where the certificates expiring soonest rise to the top and get renewed before they fail.
Fleet expiry monitoring
Paste all the hostnames you are responsible for and the tool returns each one's notAfter date and the days remaining, so the soonest expiries are easy to spot. This is the core use: a periodic sweep of every certificate you own to catch anything approaching its deadline while there is still time to renew calmly. It replaces a spreadsheet of renewal dates that inevitably drifts out of date with a live check against the certificates actually being served.
What it checks per host
For each hostname the tool connects over TLS and reports the issuer, the validity window, the days until expiry, and whether the chain builds correctly. That combination catches the two most common problems at fleet scale: certificates about to expire, and certificates served without their intermediate chain. Reviewing issuers together also surfaces surprises, like a host still on a CA you retired or a manually issued certificate that escaped your automation.
Why automate renewal, and still check
Modern certificate lifetimes are short and getting shorter; the maximum is 398 days today and the industry is moving toward far shorter windows, which makes automated renewal with tools like Certbot essential rather than optional. But automation fails quietly, a renewal hook that stopped running, a host outside the automation, a key that no longer matches. A bulk check verifies the end result, the certificate actually being served, which is the only thing your users experience.
How to use the results
Sort by days remaining and act on anything inside your renewal margin, ideally weeks not days. Investigate any host whose chain is flagged incomplete, since it may be failing silently for mobile and non-browser clients today. Re-run the sweep on a schedule, weekly is a common cadence, so new hosts and renewed certificates stay covered. For a deep look at any single host flagged here, open it in the full SSL Checker.
Frequently asked questions
- How many hostnames can I check at once?
- Paste your list and the tool checks them together, returning one row per host with issuer, expiry, days remaining, and chain health. It is designed for fleet-sized lists so you can review everything you run in a single pass rather than one lookup at a time. Very large lists simply take a little longer as each host is contacted.
- What does the days-remaining column tell me?
- It is the count of days until each certificate's notAfter date, the moment it stops being trusted. Sort by it to see what expires soonest. Act well before zero, ideally with weeks of margin, because an expired certificate is a hard, total outage for that service. This column is the heart of fleet expiry monitoring.
- I already use auto-renewal, why check in bulk?
- Because automation fails silently. A renewal hook can stop running, a host can sit outside your automation, or a renewed certificate can fail to reload. A bulk check inspects the certificate actually being served right now, which is what users hit, so it verifies that automation genuinely worked end to end rather than assuming it did.
- How often should I run a fleet check?
- A weekly sweep is a good default, giving ample lead time to renew anything approaching expiry. If your certificates are very short-lived, check more often. The goal is that no certificate ever surprises you: every one should be caught and renewed with comfortable margin, not discovered after it has already gone down.
- Does it flag missing intermediate chains?
- Yes. Alongside expiry it reports whether each host's certificate chain builds correctly, so you can catch servers that send only the leaf without its intermediate. Those often work in desktop browsers but fail for mobile and non-browser clients, so surfacing them across your fleet lets you fix a whole class of hidden trust errors.
- Can I drill into one host from the bulk results?
- For a single host, take the hostname into the full SSL Checker, which shows the complete chain, SANs, signature algorithm, HSTS, and OCSP stapling. The bulk view is for scanning many hosts to find the ones that need attention; the single-host checker is for diagnosing exactly what is wrong with any one of them.