Troubleshooting by browser

Check that Underbook is turned on and allowed on all sites: right-click its icon (or click the three dots next to it in the puzzle-piece menu), choose "This can read and change site data", pick "On all sites", then reload the hotel page.

• Turned on: open chrome://extensions and make sure the switch next to Underbook is on.
• Site access: with "When you click the extension", the banner appears only after you click the icon.
• Incognito windows: Chrome runs extensions there only if you allow it: chrome://extensions, Details under Underbook, "Allow in Incognito".
• Tabs opened before the install: reload them.
• Can't find the icon: it is under the puzzle-piece menu until you pin it.
• On a phone, Chrome does not run Underbook: use the web price checker.

Check that Underbook is turned on and allowed on all sites: open edge://extensions, choose Details under Underbook, set "Site access" to "On all sites", then reload the hotel page.

• Turned on: the switch next to Underbook on edge://extensions.
• InPrivate windows: turn on "Allow in InPrivate" on the same Details page.
• The icon: Extensions (the puzzle piece), then the eye icon next to Underbook, to show it in the toolbar.
• Tabs opened before the install: reload them.
• Your version: the Details page shows it. Edge Add-ons and the Chrome Web Store each update Underbook on their own schedule, so the two can serve different versions.

Check that you have Firefox 140 or newer on a computer and that Underbook may access your data for all websites: open about:addons, choose Underbook, turn that permission on in its permissions tab, then reload the hotel page.

• Turned on: about:addons lists Underbook as enabled.
• Private windows: on the same page, set "Run in Private Windows" to Allow.
• The icon: the newest version (from 0.5.33) puts its button on the toolbar when you install it; otherwise use the Extensions button (the puzzle piece) to pin it.
• Usage statistics are optional in Firefox: allowing technical and interaction data, or not, changes nothing about the price checks.
• Firefox for Android: Underbook is not offered there. Use the web price checker.

Right-click the Underbook icon and choose "Remove from Chrome", "Remove from Microsoft Edge" or, in Firefox, "Remove Extension"; you can also remove it from chrome://extensions, edge://extensions or about:addons.

• Everything it stored on your device goes with it, and there is no account to close.
• A price watch you set keeps running, because watches run on Underbook's service: click Unsubscribe in its email to stop it (how to stop alerts).
• Your browser then opens a short page on underbook.co that asks why you left; answering is optional.
• To keep it but quiet it for a while, turn it off with its switch on the same extensions page instead.