Does Is Localhost upload my file or text to Tool-You servers?

No. Is Localhost runs in this browser tab. Files stay on the device. Limit note: Localhost-like host check.

Should I use Private IPv4 instead of Is Localhost?

Use Is Localhost when you need Detect localhost-like hosts. Use Private IPv4 when you need RFC1918, loopback, or link-local flag. They share a category (Network) but not the same job.

Is Localhost

Detect localhost-like hosts.

Returns 1 for localhost, 127.0.0.1, ::1, or *.localhost. Unlike Private IPv4 this is loopback-focused. Unlike Is IPv4 this accepts names. Empty → 0.

What Is Localhost does

Returns 1 for localhost, 127.0.0.1, ::1, or *.localhost. Unlike Private IPv4 this is loopback-focused. Unlike Is IPv4 this accepts names. Empty → 0.

Is Localhost sits in the Network group on purpose. It is not Private IPv4 (RFC1918, loopback, or link-local flag.) and not URL Hostname (Extract host and port.). Choose this page when you need Detect localhost-like hosts. If you stretch Is Localhost into a neighbor’s job, the result will look wrong even though the site chrome looks the same.

How to use Is Localhost

Keep this tab on Is Localhost (/network/is-localhost). Pasting into the wrong Network tool (for example Private IPv4) changes the job.
Paste or type the input Is Localhost expects. Path hint: network · is localhost. Detect localhost-like hosts.
Apply the Is Localhost action only. URL Hostname is a different transform (Extract host and port.). Returns 1 for localhost, 127.0.0.1, ::1, or *.localhost. Unlike Private IPv4 this is loopback-focused. Unlike Is IPv4 this accepts names. Empty → 0.
Copy the output of Is Localhost if you need it elsewhere. Size/complexity still follows: Localhost-like host check.
If the text job is actually RFC1918, loopback, or link-local flag., leave Is Localhost and open Private IPv4.

When not to use Is Localhost

Skip Is Localhost when a neighbor tool matches better — start with Private IPv4 or URL Hostname — or when the description already warns the job will fail. In the tool’s own words: Returns 1 for localhost, 127.0.0.1, ::1, or *.localhost. Unlike Private IPv4 this is loopback-focused. Unlike Is IPv4 this accepts names. Empty → 0.

Questions about Is Localhost

What does Is Localhost do that other Network pages on this site do not?: Returns 1 for localhost, 127.0.0.1, ::1, or *.localhost. Unlike Private IPv4 this is loopback-focused. Unlike Is IPv4 this accepts names. Empty → 0. Short version: Detect localhost-like hosts.
Does Is Localhost upload my file or text to Tool-You servers?: No. Is Localhost runs in this browser tab. Files stay on the device. Limit note: Localhost-like host check.
Should I use Private IPv4 instead of Is Localhost?: Use Is Localhost when you need Detect localhost-like hosts. Use Private IPv4 when you need RFC1918, loopback, or link-local flag. They share a category (Network) but not the same job.
What are the limits of Is Localhost?: Localhost-like host check. Also: Returns 1 for localhost, 127.0.0.1, ::1, or *.localhost. Unlike Private IPv4 this is loopback-focused. Unlike Is IPv4 this accepts names. Empty → 0.