LinkedIn URL to username extractor

What the public identifier is

In linkedin.com/in/williamhgates, the williamhgates part is the public identifier — sometimes called the vanity name or slug. It is what most APIs, including ours, accept as the cheapest way to identify a profile, because passing it directly avoids a redirect lookup.

Company URLs work the same way: linkedin.com/company/google has the universal name google.

What this tool cleans up

Real URLs arrive messy. This handles the cases that break naive string splitting:

• Country subdomains — uk.linkedin.com, de.linkedin.com, www.linkedin.com
• Tracking parameters — everything after ? is discarded
• Trailing paths — /in/williamhgates/recent-activity/all/ resolves correctly
• Trailing slashes, whitespace and mixed case
• Percent-encoded characters in non-Latin vanity names

Anything it cannot parse is reported rather than silently dropped, so a bad row in a list of 500 does not disappear.

One important caveat

A public identifier is not permanent. Anyone can change their vanity URL, and when they do, the old one stops resolving.

If you are storing people in a database, store the opaque profile ID as your key — it survives a vanity change — and keep the URL as a display field. This is the single most common cause of enrichment pipelines that quietly rot: the URL you saved eighteen months ago now belongs to nobody.