CIDR to IP Range

Easily convert a CIDR notation to an IP range.


Enter a CIDR notation:


"250ok has built a best-of-breed platform that addresses the concerns of today's data-driven marketers."


Len Shneyder
VP of Industry Relations at SendGrid

See how 250ok can help monitor your reputation across your IPs.



More Free Tools

Blacklist Checker

Instantly check an IP or domain against major email blacklists including Spamhaus, SURBL, SORBS, and more.


Use Blacklist Checker


CIDR to IP Range

Enter a CIDR notation to instantly convert it to an IP range.


Use CIDR to IP Range

SPF Analyzer

SPF is a method to prevent email sender address forgery. Enter your domain to analyze its SPF record.


Use SPF Analyzer


IP Range to CIDR

Enter a IP range to instantly convert it to a CIDR notation.


Use IP Range to CIDR

DMARC Wizard

Enter your domain to analyze your DMARC record or create a DMARC policy for your domain.


Use DMARC Wizard


DNS Lookup

Perform a DNS lookup against multiple widely used nameservers.


Use DNS Lookup

Resources for #SeriousSenders


250ok will be at the Edge of the Inbox!

We’re ready to step to the very Edge of the Inbox… BrightWave’s newest event, of course! We have a long and happy partnership with BrightWave, so we’re thrilled to support a new event in Dallas on October 23 in which the brightest minds in email will gather to discuss innovation, share ideas, and build bonds. […]

You’re using a shared email tracking pixel. Will this tank your reputation?

Perhaps you knew this already, but maybe you didn’t: in some cases, Return Path supplies a shared URL in the tracking pixel it uses for engagement analytics. Much like the same discussion you see around dedicated versus shared IP environments, there’s a lot to consider when you turn over your sending reputation to people outside […]

I use a digital marketing agency. Do I need 250ok?

This is a great question we get from many marketers trying to understand how adding 250ok to their current marketing mix will change the game. With so many options for managing email campaigns, our platform and services can provide a different set of benefits depending on what you use, whether it’s a traditional email service […]




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