Build it up – the better UTM builder

Build UTM campaign links from your saved naming conventions, so your analytics stay clean.

Most UTM builders help you assemble a link. Build it up helps you keep every link the same shape, so your analytics don't quietly break. Here's the problem it solves: one teammate types "facebook", another types "Facebook", a third types "fb". Each variant is a different value in GA4, forever — UTMs can't be edited after a link has been clicked. Traffic that should show up as one channel splits into three, and every report downstream is wrong. Build it up enforces one naming convention for source, medium, and campaign, and catches mistakes before they ship: - Enforced naming: pick your values once in the options page, and every link you build pulls from that list. Free-text entry is still normalized — lowercased, hyphenated, punctuation stripped — and any correction is shown to you, never applied silently. - Near-duplicate detection: type "facebook-ad" when "facebook-ads" is already saved, and the extension flags it before you commit to a second, slightly different variant. - Paste-to-parse: paste a link that already carries UTMs and the fields reverse-fill, so you can audit or correct an existing link in seconds. - Live, color-coded preview: see exactly which part of the URL each value fills, as you type. - Recent links: your last 12 built links, one click to copy again. - Everything else on the link is left alone — existing query parameters and the fragment are preserved untouched. What it isn't: a link shortener, a URL parameter encyclopedia, or another tool that assembles UTMs without enforcing anything. Google's own Campaign URL Builder already does assembly for free. Build it up exists for the part that tool doesn't do — keeping your team from inventing new spellings of the same channel. Runs entirely on your device. No account, no sign-in, no analytics, no data sent anywhere. Your naming convention and link history are stored locally in Chrome, using only the activeTab and storage permissions you saw at install — nothing broader. Open it from the toolbar, or with Alt+Shift+U.