What is the JavaScript SDK?
The standard Userback widget works out of the box, install the snippet and users can submit feedback right away. The JavaScript SDK adds a layer of control on top of that: who sees the widget, what data gets attached to each piece of feedback, and how it fits into your site.
This is an overview. Full technical reference, parameters, and code samples live in the Developer Docs. Looking for the Mobile SDK instead? See the Mobile SDK Docs.
What you can do with it
Track users — identify logged-in users so their name, email, and account details attach to everything they submit, and you can segment by user. Two ways to do this depending on your app:
identify()for apps where users log in or switch accounts dynamically, oruser_dataif your site is static or you're using the plain JS snippet. ReferenceCreate your own feedback button — trigger the widget from your own button or UI element instead of the default launcher. Reference
Prefill fields — pre-populate name and email in the feedback form. Reference
Set the widget language in code — based on the user's language. Reference
Attach custom data — product version, feature flags, or anything else useful for context, without the user entering it themselves. Reference
Customize the widget — change its look, or show/hide it, based on page or user variables. Reference
Full parameter reference for every method: JavaScript SDK docs.
FAQ
Q: Can I use Userback without showing the widget button?
A: Yes. Hide the default launcher under Edit Widget → Target → Do not display the launcher, then trigger feedback manually with the SDK.
Q: What plan do I need?
A: Business plan and above. See pricing for a full comparison.
Q: Can I pass data without the user entering it themselves?
A: Yes. Attach any data point silently — plan type, user ID, feature flags — to every submission. Users never see it; your team gets full context in the inbox.
Related articles: Developer Tools: Console Logs and Network Requests · How to Install Userback on Your Website or Mobile App · Best Practices for Developers in Userback · Smarter Surveys with the Userback JavaScript SDK