URL Validator
Validate one or many URLs with the same parser browsers use. Flags missing schemes, spaces, invalid hosts, credentials, plain http and shows the normalized URL.
Up to 200 lines are checked with the same URL parser that browsers use (WHATWG URL Standard).
https://example.com/path?q=1- ✓ Parsed successfully (scheme: https).
What is URL Validator?
This URL validator checks up to 200 URLs at once against the WHATWG URL Standard, the specification every modern browser implements. Each URL gets a Valid/Invalid verdict plus practical warnings: missing scheme, spaces, hosts without a TLD, labels that DNS rejects, underscores, private hosts, embedded credentials, plain http, explicit default ports and very long URLs.
How to use URL Validator
- Paste one URL per line.
- Optionally tick "Only accept http:// and https:// URLs" for web links.
- Read the verdict and the list of checks for each line.
- Use the normalized URL shown when the browser would rewrite the input.
Example
example.com HTTPS://Example.COM:443/a/../b
Line 1: Invalid – the scheme is missing. Line 2: Valid – normalized to https://example.com/b; port 443 is the default and is removed.
When to use URL Validator
Use it to clean lists of links before importing them, to validate user input rules, or to understand why a URL fails in code. It checks syntax only – it does not request the URL, so it cannot tell whether the page exists or returns 404; use the Redirect Checker or HTTP Headers Checker for that.
How URL Validator works
Each line is passed to new URL(). If parsing throws, the URL is invalid, and the tool explains the most likely reason (e.g. a missing scheme). If it parses, extra rules are applied to the host: labels up to 63 characters, names up to 253, no leading or trailing hyphens, and checks for private ranges. Because the WHATWG parser silently drops a default port, the raw input is also inspected for :80/:443. Warnings never change the WHATWG verdict.
Common Use Cases
- Validate a spreadsheet column of website URLs before a CRM import.
- Find links in a sitemap draft that contain spaces or missing schemes.
- Check how a browser normalizes a URL with uppercase hosts or ../ segments.
- Spot links that still use plain http.
FAQs
Is a URL without https:// valid?
Not as an absolute URL. Browsers' address bars guess the scheme, but the URL Standard and most APIs require it.
Are URLs with spaces valid?
The WHATWG parser rejects spaces in the host and percent-encodes them elsewhere, but you should encode them as %20 yourself so other software handles them.
Does a valid URL mean the site exists?
No. This tool never contacts the URL; it only checks the syntax.