SSL Certificate Expiry Check Script Generator
Generates OpenSSL commands, Bash batch scripts, and Python scripts for checking SSL certificate expiry from a domain list — the tool itself makes no network requests; you run the output locally.
FreeOnline Tool
Loading…
How to Use
- Enter the domains you want to check in the "Domains" textarea, one per line (comma-separated also works).
- Set the check port (default 443) and the alert threshold in days (default 30 — certificates expiring within this window get flagged).
- Click "Generate Commands" and switch between the three tabs (OpenSSL Command / Bash Script / Python Script) to view different output formats.
- Copy the generated command or script and run it in your own terminal or on a server — the tool page itself never connects to any domain.
- Click "Load Sample Data" to quickly fill in four example domains (example.com, google.com, github.com, cloudflare.com).
Features
- Accepts a batch list of domains (newline or comma separated) and generates certificate-check commands for all of them at once.
- Configurable check port and alert threshold in days, which is baked directly into the generated script logic.
- Produces three output formats: a single-line OpenSSL command, a ready-to-run Bash batch script (with CRITICAL/WARNING/NOTICE/OK severity levels), and a Python script using the ssl/socket module (with the same four severity levels).
- Both the Bash and Python scripts automatically compute days remaining and classify each domain as ≤7 days / ≤14 days / ≤threshold / OK — ready to drop into a cron job or CI pipeline.
- Explicitly does not perform any live checking itself — it only produces text in the browser; no data is sent or stored.
Use Cases
Batch certificate audits for ops teams
An ops engineer managing dozens of domains generates a single Bash script to drop into crontab, catching expiring certificates before they cause an outage.
Wiring certificate checks into CI/CD
A DevOps engineer needs a certificate health-check step in the deployment pipeline and copies the generated Python script straight into the CI config instead of writing detection logic from scratch.
Quick one-off lookup for a single domain
Need the exact expiry date for one domain right now — copy the generated OpenSSL one-liner into a terminal and run it immediately, no need to remember the openssl flags.
Learning certificate-check command syntax
An engineer new to SSL operations uses the generated, fully readable scripts to learn how openssl s_client/x509 and Python's ssl module are used to check certificate expiry.
FAQ
Does this tool automatically check whether my website's certificate has expired?
No. The tool only generates check commands and script text locally in your browser — it never makes a network request to any domain. Copy the generated command to your own terminal or server to get real results.
Why offer OpenSSL, Bash, and Python formats?
Each suits a different scenario: OpenSSL for a quick manual check of one domain, Bash for dropping into a Linux server's crontab for scheduled batch checks, and Python for integrating into an existing ops toolchain or CI/CD pipeline.
What does the alert threshold do?
It's embedded into the generated Bash and Python script logic: ≤7 days remaining is flagged CRITICAL, ≤14 days WARNING, ≤threshold days NOTICE, and anything beyond that is OK — so you can triage results at a glance.
Can the generated scripts run on Windows?
The Bash script needs Linux/macOS or WSL. The Python script uses only the standard library (ssl/socket) and is cross-platform — any machine with Python 3 works. The OpenSSL command requires OpenSSL to be installed locally.
What format should the domain list be in?
One domain per line, or comma-separated. No protocol prefix needed (no https://) — just the bare domain, e.g. example.com.