Free Website, DNS and Email Tools

Website and SSL checks

Check a website the way your visitors and search engines reach it. Each tool runs a live request from our server in the UK when you press the button, with no account needed.

SSL Checker - See when a site's certificate expires, who issued it, whether the chain is trusted and whether it covers the name
Website Down Checker - Find out whether any website or page is down for everyone or just you, with its HTTP status, response time, SSL and DNS
Domain Expiry Checker - See when a domain name expires, its registrar and nameservers, live from the registry
Robots.txt Checker - Fetch and validate a site's robots.txt rules and sitemap directives, as a browser and as Googlebot
Uptime and SLA Calculator - Convert an uptime percentage into the downtime it allows per day, month and year

Network and scheduling utilities

Everyday calculators and lookups for configuring networks and scheduled jobs:

DNS Record Lookup - Query A, AAAA, CNAME, MX, NS, TXT and SOA records for any domain
DNS Propagation Checker - Compare your domain's own nameservers with 8 public resolvers after a DNS change
IPv4 Subnet Calculator - Work out network ranges, host addresses and subnet masks for IPv4 networks
IPv6 Subnet Calculator - Find network addresses, host ranges and prefixes for IPv6
Cron Expression Builder - Build and read crontab schedules without syntax errors

30s

Fastest check interval

24/7

Always-on monitoring

Check locations

Native alert channels

DNS and Email Authentication Lookups

Query individual DNS record types and verify the records that protect email deliverability:

A Record Lookup - Resolve a domain to its IPv4 addresses
AAAA Record Lookup - Resolve a domain to its IPv6 addresses
CNAME Record Lookup - Reveal the canonical hostname an alias points to
MX Record Lookup - List the mail servers that accept email for a domain
Nameserver Lookup - Identify the authoritative nameservers for a domain
TXT Record Lookup - Read TXT records, including verification and policy strings
SOA Record Lookup - Inspect the start of authority record and zone serial
SRV Record Lookup - Discover service location records for a domain
CAA Record Lookup - See which certificate authorities may issue for a domain
Reverse IP Lookup - Find the hostname associated with an IP address
SPF Record Checker - Validate the Sender Policy Framework record for a domain
DMARC Record Checker - Review the DMARC policy that protects a domain from spoofing
DKIM Record Checker - Verify the DKIM signing record for a selector

Which tool do I need?

Start from the question you are trying to answer:

Is a site down for everyone, or just me? Use the website down checker. It requests the exact URL from our UK server and shows the status code, response time, SSL and DNS.
When does my SSL certificate expire, and is it trusted? The SSL checker shows the expiry date, issuer, chain and whether the certificate covers the name.
When does my domain expire? The domain expiry checker reads the registry record, with the registrar and nameservers.
Has my DNS change gone live? The DNS propagation checker compares your domain's own nameservers with 8 public resolvers.
Where does email for a domain go? The MX lookup lists the mail servers in priority order.
Why is my email landing in spam? Check the SPF, DKIM and DMARC records, the three things receiving mail servers test.
Which certificate authorities may issue for my domain? The CAA lookup shows the issue, issuewild and iodef records.
Can Googlebot crawl my pages? The robots.txt checker tests your rules as a browser and as Googlebot.
How much downtime does 99.9% allow? The uptime calculator converts any percentage into downtime per day, month and year.
What is the crontab line for every weekday at 9am? The cron expression builder writes it and explains it back.

Professional tools. Completely free.

No account needed to get started.

Try it free

Watching a page for changes

To be told when specific text appears on, or disappears from, a page, such as a stock label, a price or a line of policy wording, PulseStack™ uses a keyword monitor that checks the page on a schedule. That is part of the paid plans rather than a free tool. Website change detection explains how it works, how to choose the text to watch and what it cannot see.

From a one-off check to monitoring

The free tools answer a question once. PulseStack™ asks it on a schedule and alerts you when the answer changes:

Website monitoring - Availability and response time, checked from London, New York and Sydney
SSL certificate monitoring - An alert before a certificate expires or stops being trusted
Domain expiry monitoring - A warning before a domain registration lapses
Cron job monitoring - Confirmation that scheduled tasks actually ran
Keyword monitoring - An alert when text appears on, or disappears from, a page
Status pages - A public page that shows your live status and uptime history

PulseStack™ checks your sites from London, New York and Sydney and alerts you on eight native channels. The free plan covers 5 monitors.

Built in the UK. Free plan, no card required.

Start for free

Free to use, no account required

Every tool on this page is free and needs no signup or personal details. The checks run live from our server when you ask, and the results are not saved. To keep them quick for everyone, each tool has a fair-use limit on how many checks one visitor can run a minute.

When you are ready to monitor continuously rather than check on demand, PulseStack™ turns the same checks into scheduled uptime, SSL, cron and keyword monitoring, with alerts across 8 native channels, starting on a free plan.

Common Questions About Our Free Tools

Are these tools completely free?

Yes. Every tool is free to use, with no registration. A fair-use limit stops any one visitor running hundreds of checks a minute.

Do I need to create an account?

No. The tools work straight away, without an account or any personal information.

What monitoring does PulseStack™ offer?

The Free plan includes 5 website monitors with 5-minute checks, email alerts and a public status page, with no card needed. Paid plans from £9 a month add faster checks and every monitor type, including SSL certificate, domain expiry, DNS, keyword, API and cron job monitoring.