The short-link glossary.

Attribution

Crediting a visit, signup or sale to the marketing touch that drove it — the answer to "which link, channel or campaign actually produced this?" On a short link, attribution is the data you capture on every click: the channel it came from, the UTM parameters carried in the URL, and the referrer. Get attribution right and you can stop guessing which efforts are worth repeating.

See also UTM parameters explained

Bounce

A visitor who lands on your page and leaves without a second interaction — no click, no scroll-triggered event, no next page. A high bounce rate on traffic from a particular link usually means the destination didn't match the promise of the link or the ad. Worth watching per-channel: a campaign with lots of clicks but heavy bounce is spending attention without earning it.

Branded domain (custom domain)

Serving your short links from your own domain — go.acme.com/sale instead of a generic shortener's host. You point a subdomain at the shortener with a CNAME DNS record, and every link you create lives under your brand. Branded links look trustworthy, reinforce recognition, and reliably earn more clicks than anonymous ones.

See also Why branded links get more clicks

Channel

The surface a click came through — email, organic social, paid search, QR scan, a partner newsletter. slsh.me tags each visit with a channel so you can compare where attention actually originates. Channel is the coarse grouping; UTM parameters add the fine-grained source/medium/campaign detail underneath it.

Click-through rate (CTR)

The share of people who saw your link and clicked it — clicks divided by impressions, as a percentage. CTR tells you how compelling the link, copy or creative was at the moment of decision. A short, branded, well-previewed link almost always out-clicks a long raw URL, which is why CTR is the metric most directly improved by good link hygiene.

Cloaking

Showing search engines or scanners one destination while sending real users to another — a deceptive cousin of link masking. Legitimate link masking keeps a branded URL in the address bar; cloaking deceives the visitor or crawler about where they're really going, and search engines penalise it. Know the line between the two before you reach for either.

See also Link masking vs cloaking

Deep link

A URL that opens a specific screen inside an app rather than its home screen or a web fallback — tapping it jumps straight to a product, a profile or a checkout in the native app if it's installed. Deep links make a shared link feel seamless on mobile; pair them with a short link and you keep the tidy, trackable URL while still landing people exactly where you intend.

Link masking

Keeping a branded short URL visible in the address bar after a click, instead of revealing the long destination. Done honestly it's a presentation choice — the visitor still reaches the real page. Done to hide a destination from the user, it shades into cloaking, which carries real SEO and trust costs. The distinction is whether anyone is being misled.

See also Link masking vs cloaking

Link preview

The card that appears when you paste a URL into Slack, iMessage, LinkedIn or X — title, description and image, pulled from the page's Open Graph and Twitter-card tags. A missing or broken preview makes a link look untrustworthy and tanks its click-through rate. When a preview won't render, the cause is almost always a missing tag, a too-large image, or a stale cache.

See also Why your link preview isn't working · free OG preview checker

Open Graph (OG)

The metadata protocol that controls how your page looks when it's shared. A handful of <meta property="og:*"> tags — og:title, og:description, og:image — tell Facebook, LinkedIn, Slack and most other platforms what title, blurb and image to show in the link preview. The image is the highest-leverage one: a clean 1200×630 card is what makes a shared link stop the scroll.

See also The Open Graph tags that matter · OG preview checker

QR code

A square barcode that encodes a URL so a phone camera can open it instantly — the bridge from print, packaging and screens to the web. Point a QR code at a short link rather than a raw URL and you get two wins: a denser, easier-to-scan code, and the ability to track every scan as its own channel without reprinting anything.

See also How to track QR-code scans · free QR code generator

Redirect (301 vs 302)

The mechanism behind every short link: the shortener answers the request with an HTTP redirect that forwards the browser to the real destination. The status code says whether the move is permanent or temporary. A 301 is a permanent redirect — search engines pass link equity through and cache it hard. A 302 is temporary — equity stays with the short URL and the redirect is re-checked each time, which is what you want when the destination might change.

See also 301 vs 302 redirects · free redirect checker

Referrer

The page a visitor came from, sent by the browser in the Referer header (the original spec misspelled it, and the typo stuck). It's a clue to where a click originated — but it's unreliable: many apps strip it, HTTPS-to-HTTP loses it, and privacy settings suppress it. That unreliability is exactly why UTM parameters exist — they put the source in the URL itself, where it survives.

Short link

A compact URL that redirects to a longer destination — slsh.me/sale standing in for a sprawling, UTM-laden address. Short links are easier to share, look cleaner in print and social, and, because every click passes through the shortener, they're trackable: you see how many people clicked, from where, and when. They're the unit everything else in this glossary hangs off.

See also create a free short link

Slug

The part after the slash that uniquely identifies a short link — the sale in slsh.me/sale. A random slug (slsh.me/a7Xq2) is auto-generated and compact; a custom slug is one you choose to make the link readable and on-brand. Memorable, descriptive slugs are easier to say out loud, type from a poster, and trust — so they tend to get clicked more.

Twitter / X card

X's own flavour of link preview metadata. A few <meta name="twitter:*"> tags — chiefly twitter:card, twitter:title and twitter:image — tell X how to render your shared link. X falls back to Open Graph tags when these are missing, so the usual fix for a card that won't show its image is a too-large or wrong-format image, or a cache that needs refreshing.

See also Why your X card image won't show

UTM parameters

The five tracking tags you append to a URL so analytics knows where a visit came from. They travel in the query string and are read by GA4 and most analytics tools:

utm_source — the specific origin (newsletter, twitter). utm_medium — the channel type (email, cpc, social). utm_campaign — the campaign the link belongs to (spring-sale). utm_term — the paid-search keyword. utm_content — which creative or variant.

Because values are matched as exact, case-sensitive strings, a consistent naming convention is what keeps one campaign from splitting across several rows in your report.

See also source vs medium vs campaign · UTM naming convention · free UTM builder

URL encoding

Replacing characters that aren't safe in a URL with %-escapes so the link survives intact — a space becomes %20, an ampersand %26. It matters most for UTM values: a stray space or unencoded symbol can truncate your tracking or split a campaign value, so anything you bolt onto a query string should be encoded first.

See also free URL encoder / decoder

Vanity URL

A deliberately readable, brand-flavoured link built to be remembered and trusted — acme.com/webinar rather than acme.com/p?id=8841. In short-link terms it's the combination of a branded domain and a meaningful custom slug. Vanity URLs are the ones you can read aloud on a podcast or print on a flyer without anyone fumbling the spelling.

See also branded short links