Slug Validator

Check if a string is a valid URL-friendly slug.

freeworks offlinenothing uploaded
Input
Output
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About slug validator

Slug Validator runs in the page as you use it. There is no input to submit and no result to fetch, because the whole thing happens on this side of the wire.

The parsing, the maths and the formatting all happen in JavaScript on this page. No request carries your input anywhere, because there is no endpoint for one to reach.

You will find it under Validators, alongside 17 other tools for the same sort of job.

Validates lowercase letters, numbers, and hyphens per SEO best practices.

How to use it

01
Start it
Every control is on the tool itself. Keyboard shortcuts, where there are any, are listed beside it.
02
Watch it run
It updates in the page as you go. Nothing is sent anywhere, so it keeps working with the network off.
03
Close when done
Nothing is stored between visits. Reloading gives you a clean start rather than picking up where you left off.

Examples

Valid Slug
Validate a well-formed URL slug
Input
my-awesome-blog-post
Output
Valid slug: my-awesome-blog-post
Invalid Slug
Detect issues in a slug with uppercase and spaces
Input
My Blog Post
Output
Invalid slug: Should be lowercase; Should not contain spaces; Should only contain lowercase letters, numbers, and hyphens

Questions

Does Slug Validator work offline?+

Yes. It is JavaScript running in this tab, so once the page has loaded it needs nothing further from the network. Put the machine in flight mode and it carries on. Nothing you do here is sent anywhere, because there is nowhere for it to go.

Does it remember anything between visits?+

No. Reload the page and it starts from nothing. There is no account, no saved state and no cookie holding your last session. That is a deliberate trade: it cannot lose your data because it never keeps any.

Is it accurate?+

Timing comes from performance.now(), the high resolution clock the browser provides, rather than from setInterval, which drifts by a few milliseconds every tick and compounds over minutes. What can still shift things is the browser throttling a tab in the background, so leave it visible if the timing matters.

Does it make a sound?+

Where a sound makes sense, it is generated with the Web Audio API rather than loaded as a file, so there is nothing to download and nothing to block. Browsers refuse to start audio until you have interacted with the page, which is why the first press is what switches it on.

Can I use Slug Validator on a phone?+

Yes. The controls are sized for touch and the layout collapses to one column on a narrow screen. Bear in mind that a phone locking its screen will suspend the page, and timing stops with it.