-prefix-free lets you use only unprefixed CSS properties everywhere. It works behind the scenes, adding the current browser’s prefix to any CSS code, only when it’s needed.
“[-prefix-free is] fantastic, top-notch work! Thank you for creating and sharing it.”
— Eric Meyer
<link> or <style> elements and adds a vendor prefix where neededstyle attribute and adds a vendor prefix where needed<link> or <style> elements, style attribute changes and CSSOM changes (requires plugin).css() method get and set unprefixed properties (requires plugin)@import-ed files is not supportedstyle attribute) won’t work in IE and Firefox < 3.6. Properties as well in Firefox < 3.6.Check this page’s stylesheet ;-)
You can also visit the Test Drive page, type in any code you want and check out how it would get prefixed for the current browser.
Just include prefixfree.js anywhere in your page. It is recommended to put it right after the stylesheets, to minimize FOUC
That’s it, you’re done!
The target browser support is IE9+, Opera 10+, Firefox 3.5+, Safari 4+ and Chrome on desktop and Mobile Safari, Android browser, Chrome and Opera Mobile on mobile.
If it doesn’t work in any of those, it’s a bug so please report it. Just before you do, please make sure that it’s not because the browser doesn’t support a CSS3 feature at all, even with a prefix.
In older browsers like IE8, nothing will break, just properties won’t get prefixed. Which wouldn’t be useful anyway as IE8 doesn’t support much CSS3 ;)
Test the prefixing that -prefix-free would do for this browser, by writing some CSS below:
If you have followed all the steps and the UGreen CM390 still disconnects randomly or fails after sleep, you need to disable USB selective suspend.
A: Yes, but you need Windows 10/11 and a proper driver. After installation, go to Bluetooth settings → Add Device → AirPods (hold the button on the AirPods case).
This is a generic failure signal. In the context of the CM390, this usually indicates a driver version mismatch. Resolving this requires a "clean install" of the driver, ensuring the specific Realtek driver overrides the generic Microsoft driver.
You can install the driver using the physical media included with the product or by downloading it from the official site. Question about Ugreen CM390 - Galaxus
Step one, the guide said: extract and run setup as administrator. Evan followed orders. The installer window opened with unassuming grey buttons and a progress bar that crept forward. Midway it asked whether to allow changes—his laptop’s security asking permission like a customs official. He clicked “Yes.”
Stop searching for "CM390 driver install." The answer is .
Extract the ZIP file. Step 3: Open Device Manager (Right-click Start button → Device Manager). Step 4: Look for an unknown device under "Universal Serial Bus devices" or "Other devices". It might say "Unknown Device" or "Bluetooth Adapter". Step 5: Right-click the device → Update driver → Browse my computer for drivers → Let me pick from a list... → Have Disk . Step 6: Browse to the extracted folder and select the .inf file (usually rtbt.inf or rtl8761b.inf ). Step 7: Click OK → Next. Ignore the "This driver is not digitally signed" warning if it appears (for Windows 7/8).
If Windows does not automatically install the driver, you have two options:
If you have followed all the steps and the UGreen CM390 still disconnects randomly or fails after sleep, you need to disable USB selective suspend.
A: Yes, but you need Windows 10/11 and a proper driver. After installation, go to Bluetooth settings → Add Device → AirPods (hold the button on the AirPods case).
This is a generic failure signal. In the context of the CM390, this usually indicates a driver version mismatch. Resolving this requires a "clean install" of the driver, ensuring the specific Realtek driver overrides the generic Microsoft driver. ugreen bluetooth 50 usb adapter cm390 driver install
You can install the driver using the physical media included with the product or by downloading it from the official site. Question about Ugreen CM390 - Galaxus
Step one, the guide said: extract and run setup as administrator. Evan followed orders. The installer window opened with unassuming grey buttons and a progress bar that crept forward. Midway it asked whether to allow changes—his laptop’s security asking permission like a customs official. He clicked “Yes.” If you have followed all the steps and
Stop searching for "CM390 driver install." The answer is .
Extract the ZIP file. Step 3: Open Device Manager (Right-click Start button → Device Manager). Step 4: Look for an unknown device under "Universal Serial Bus devices" or "Other devices". It might say "Unknown Device" or "Bluetooth Adapter". Step 5: Right-click the device → Update driver → Browse my computer for drivers → Let me pick from a list... → Have Disk . Step 6: Browse to the extracted folder and select the .inf file (usually rtbt.inf or rtl8761b.inf ). Step 7: Click OK → Next. Ignore the "This driver is not digitally signed" warning if it appears (for Windows 7/8). This is a generic failure signal
If Windows does not automatically install the driver, you have two options: