How URL shorteners affect link previews

A shortened link adds a redirect between the shared URL and your page, and what appears in the preview depends on how the shortener handles crawlers. Most redirect and let the destination’s tags win. Some serve their own tags at the short URL, which overrides your page entirely.

Knowing which kind you’re using explains why some shortened links preview correctly and others don’t.

The pass-through case

The common behaviour. The short URL returns a 301 or 302 to your page, the crawler follows it, reads your tags, and builds a card from your page.

Result: the preview is identical to sharing the long URL. The shortener is invisible in the card, except that some platforms display the short domain as the source rather than yours — which is a branding consideration rather than a technical problem.

Requirement on your side: nothing special. Correct tags on the destination, as always.

The override case

Some shorteners serve an HTML page at the short URL containing their own Open Graph tags, with a redirect for real browsers. A crawler reads those tags and never reaches your page.

This is how “customise your link preview” features work, and it’s a legitimate capability with an obvious hazard: whoever controls the short link controls what the card says, regardless of what the destination page actually contains.

The honest use is customising the preview of content you own — a title tuned for one audience, an image sized for one platform, without editing the page. The dishonest use is making a link look like it points somewhere it doesn’t, which is a phishing technique, and it’s why some platforms treat shortened links with suspicion.

If you use a shortener with this feature, the constraint is straightforward: only override previews for destinations you control, and keep the card an accurate description of the page.

Diagnosing which you have

Follow the redirect chain and look at what’s served:

curl -sIL https://short.example/abc | grep -i '^HTTP\|^location'

Each hop shows as a status and a location. Then check whether the short URL itself carries tags:

curl -s https://short.example/abc | grep -i 'og:'

If tags appear at the short URL, it’s an override shortener. If you get only a redirect, it passes through.

Chain length matters

Crawlers follow redirects, with limits and varying tolerance. Long chains are where previews get unpredictable.

Chains grow without anyone deciding to build one: a shortener pointing at a marketing redirect pointing at a locale redirect pointing at a trailing-slash redirect. Four hops, each individually reasonable.

Keep it to one hop where you can. Two is usually fine. Beyond that, expect some platforms to give up, and expect the failure to be inconsistent between platforms — which is a miserable thing to debug.

While you’re checking: make sure the chain doesn’t loop, doesn’t cross between HTTP and HTTPS, and ends at a page whose og:url is its own canonical address.

Trade-offs of shortening at all

In favour: short links fit character limits, survive being read aloud or printed, and — the real reason most people use one — give you click counts and the ability to change the destination after sharing.

Against: an extra hop, a foreign domain in the card’s source label, and a general association with spam that makes some platforms and some readers treat shortened links as lower-trust. Also a dependency: if the shortener disappears, every link you’ve published breaks. That’s a genuine archival risk for anything long-lived.

For links in printed material or where you need post-publication redirection, shortening earns its place. For an ordinary social post where the platform already handles long URLs, it mostly costs you the domain in the preview.

Your own short domain

The middle path: run shortening on a domain you own, so the card’s source label is a domain readers recognise. It also removes the third-party dependency on the shortener continuing to exist, which is the more serious of the two problems.

The dependency doesn’t vanish, it moves — you now have to keep that domain and its redirect map alive indefinitely. Worth it if you publish links that need to outlive a campaign.

Practical rules

Correct tags on the destination, always. Everything else is layered on top of that.

One hop if possible. Check the chain rather than assuming.

Know whether your shortener overrides previews, so you’re not debugging a page whose tags never get read.

Only override previews for content you own, and keep them accurate.

Test the short URL, not the long one. They can behave differently, and the short one is what people will paste.