Widget performance
How heavy is the Zendesk Chat chat widget?
DebugBear measured it at 533KB. Here is what that means for your page, how it compares, and how to check your own installation.
Last checked 1 September 2026
Widget size/Zendesk Chat
The short answer
How big is the Zendesk Chat chat widget?
DebugBear measured the Zendesk Chat chat widget at 533KB of download and about 991ms of JavaScript execution. That places it 2 of 7 among the mainstream widgets they tested, which ranged from 79KB to 749KB. For scale, that is roughly 21 times the 26KB TGLiveChat widget.
The heaviest widget DebugBear measured for JavaScript execution. In their words, Zendesk "takes almost a second of CPU time".
What Zendesk Chat is
The chat component of the Zendesk support suite.
How it compares
| Widget | Download | JS execution |
|---|---|---|
| Tawk.to | 749 KB | Not published |
| Zendesk Chat | 533 KB | 991 ms |
| Drift | 464 KB | Not published |
| LiveChat | 385 KB | Not published |
| Intercom | 301 KB | Not published |
| Crisp | 155 KB | Not published |
| LiveAgent | 79 KB | Not published |
| TGLiveChat | ~26 KB | not in the test |
Competitor figures are DebugBear's, updated 10 November 2025. The TGLiveChat figure is our own measurement, with the method on the widget size page.
Where Zendesk Chat is the better choice
If your company already runs Zendesk, the chat that comes with it lives in the same inbox as everything else, which is worth more than any feature comparison.
Where we are different
Flat pricing, and a widget that does not spend most of a second of CPU on the visitor device.
Worth being plain about the trade: TGLiveChat is not a helpdesk. There is no ticketing, no SLA engine, no assignment rules and no reporting suite. If you were using those, a lighter widget is not a saving, it is a downgrade. If you were not, you were carrying the weight of a product you never opened.
Measuring your own installation
Every published figure, including ours, is somebody else's configuration. Open DevTools, go to the Network tab, filter by the vendor domain and hard reload. Read the transfer column, not the resource size column. Then look at the Performance tab for scripting time. Two minutes, and it is the only number that describes your site.
The bottom line
Zendesk Chat downloads 533KB. Whether that is a problem depends entirely on what you get for it. A heavy widget attached to a helpdesk your team lives in is a fair trade. A heavy widget attached to a chat bubble nobody answers is not.
Defer it before you replace it. That is the cheaper fix and it usually works.
Frequently asked questions
How big is the Zendesk Chat chat widget?
Does the Zendesk Chat widget hurt Core Web Vitals?
How do I make Zendesk Chat load faster?
How do I measure this myself?
Is there a lighter alternative to Zendesk Chat?
What does Zendesk Chat do well?
Sources and references
- DebugBear: How Do Different Chat Widgets Impact Site Performance? Published 14 July 2019, updated 10 November 2025. Source of the Zendesk Chat figures on this page.
- Google: Core Web Vitals What widget weight actually affects, and how.
- Chrome DevTools: Network reference The transfer versus resource size distinction used above.
Measurements of Zendesk Chat belong to DebugBear and are cited for comparison. We measure our own widget and nobody else's.