progress()Baseline · Newly available
The progress() CSS function returns a ratio for the relative position of one value between two other values, clamped between 0 and 1. You can use it to interpolate a value for other calculations.
Works in the latest version of every major browser, but older devices may not support it yet. Baseline since Sep 1, 2026.
Browser support
DesktopChrome
1–137Not supported
138+Supportedsince Jun 24, 2025
Current: 155Edge
12–137Not supported
138+Supportedsince Jun 26, 2025
Current: 154Firefox
1–154Not supported
155+Supportedsince Sep 1, 2026
Current: 157Safari
1–18.6Not supported
26+Supportedsince Sep 15, 2025
Current: 27MobileChrome Android
18–137Not supported
138+Supportedsince Jun 24, 2025
Current: 155Firefox Android
4–154Not supported
155+Supportedsince Sep 1, 2026
Current: 157Safari iOS
1–18.6Not supported
26+Supportedsince Sep 15, 2025
Current: 27How to use
Every current browser supports this, but it only became Baseline on Sep 1, 2026. Use it as a progressive enhancement, or keep a fallback if you support older devices.
Example
Full syntax and examples are on MDN: progress.
Feature detection
There’s no simple runtime check for this feature; rely on the support table and test in your target browsers.