Preview version B
See your new version on your own website before anyone else does. Only your browser tab shows it, and nothing is counted.
Before your impact check sends real traffic to a variant, see it with your own eyes. Preview B opens your live site with the change applied, for you alone.
Preview B opens your own website showing your new version, only for you. You can check that it looks right before any visitor sees it.
Think of a dress rehearsal
Before opening night, actors run the whole show with no audience. If a door sticks, they fix it then, not in front of a full theater. A preview is your dress rehearsal.
When you can use it
- Split tests made with the visual editor, including ones that send visitors to another page.
- Before you start, and while the check is running.
- Checking a check that's On hold because the split between the versions looks off (more).
- Split test (developer) checks: your developer's code decides what B looks like, so ask them to show you.
- Before vs after and Adoption checks: the change is already live for everyone.
- Viewers: only Owners and Editors see the preview buttons (roles).
Preview before you start
- 1On your project page, press + New impact check.
- 2Finish What are you shipping? and Which needle should it move?
- 3In How should we test it?, press Preview B on my site.
- 4Your website opens in a new tab, showing version B.
Pressing it saves your check as a Draft. Nothing is measured until you press Start measuring.
Preview on the check page
At the top of the check page, Preview A and Preview B sit side by side while the check is a draft or running. Preview A shows your site as it is today. Preview B shows your change.
What you see
- Your website opens on its home page, in a new tab. Go to the page you changed. The preview stays on while you click around in that tab.
- A dark label in the bottom left corner says Needlr preview, which version you're looking at, and the name of the change.
- Show A (or Show B) switches to the other version, so you can compare.
- Exit ends the preview and shows your site as everyone sees it. Closing the tab ends it too.
Who sees it
- Only you, in that one tab. Your visitors don't see anything different.
- Nothing you do in a preview is counted.
- While a preview is on, Needlr treats that browser as your team's, so its other tabs are kept apart too (why that matters). That ends when you press Exit or the link runs out. After that, your visits count like anyone else's.
Sharing a preview
The preview link works for 30 minutes. It disappears from the address bar as soon as your site opens, so it isn't meant to be copied or sent. If it has run out, the label may say link expired: press Preview B again.
To show a teammate, ask them to press Preview B themselves (they need to be an Owner or Editor), or share your screen.
If it doesn't work
- No preview button in step 3: it shows only for visual editor split tests, once the Needlr snippet is live on your site and steps 1 and 2 are done.
- The buttons on the check page are grey: the Needlr snippet isn't live on your site yet. Publish to your Tag Manager first.
- Add your website on the project page first. Needlr needs your site's address to open it (your website).
- Nothing opens: your browser may have blocked the new tab. Allow pop-ups for Needlr and try again.
Common mistakes
- Checking only on a big screen. Make the window narrow too, to see roughly how it looks on a phone.
- Testing the change by clicking around your live site. Those visits can be counted. Use the preview: it never is.
- Skipping the preview. A broken version B can cost you a week of visitors before anyone notices.
What the video says
Before your impact check sends real traffic to a variant, see it with your own eyes. Preview B opens your live site with the change applied, for you alone.
In the wizard, it sits in step 3, How should we test it, once the change and the KPI are set. Pressing it saves a draft. Nothing is measured yet.
Later, the check page has Preview A and Preview B side by side. Flip between the current page and your change to confirm the variant renders cleanly.
The preview lives in that one browser tab. A dark label in the corner shows which version you're on, with Show A to compare and Exit to leave.
Nothing in a preview is counted, and your real visitors never see it. Until the preview ends, that browser is marked as team traffic and stays out of every result.
The link lasts 30 minutes and isn't for sharing, so teammates open their own preview. A two-minute look now beats a broken variant eating a week of traffic.