Printing preview blanks may be caused by cache exceptions or improper settings. 1. Clear UC browser cache and restart; 2. Check the paper size, direction and turn off options such as "Hide Background Graphics"; 3. Save the web page as PDF and print with PDF application; 4. Try to enable desktop mode or replace it with Chrome or Edge browser to print to eliminate compatibility issues.

All or delete individual download records to manage privacy. You can clear all records by setting → Privacy and Security → Clear browsing data, check the download content and select all time; or visit the chrome://downloads page, click the three-point button on the right side of a specific download item, and select Remove from the list to achieve single or batch deletion.

There are three ways to change the default PDF opening method to your desired application: through File Explorer, System Settings, or Control Panel. First, you can right-click on any PDF file and select "Open with" and check "Always use this app"; secondly, enter the "Default Application" setting through [Win I] and specify a program for .pdf; you can also manually associate it through the "Default Program" function of the control panel. If it is still changed after setting it, you need to check whether the security software has reset the association, and make sure that the PDF reader's own settings have been set to default to avoid conflicts between multiple PDF software and lead to unstable association.

1. Turn on the reading mode of UC Browser to bypass copy restrictions. Click the book icon and long press the text to copy; 2. Disable JavaScript to remove script protection. Go to settings to turn off this function and refresh the page; 3. Use the webpage snapshot function to load content in a simplified form, peel off the control script and freely select to copy; 4. Trigger text re-rendering through the translation function to invalidate the anti-copy script to complete the copy.

If Google Chrome freezes, freezes, or crashes, you can try adjusting the hardware acceleration settings. First turn it on or off through the "Use Hardware Acceleration Mode" switch in the browser settings, and restart the browser; if the problem persists, go to the chrome://flags page, search for gpu-related options, disable experimental features such as Hardware-accelerated videodecode, GPUrasterization, and Zero-copyrasterizer, and then restart the browser to apply the changes.

Log in with a QQ account to synchronize multiple devices, and it is recommended not to exceed 3 devices; WeChat login only supports single device online, which is suitable for occasional use. Choose a more appropriate method based on your usage habits.

Turn on incognito browsing in UC Browser to protect privacy. Select "Incognito Browsing" through the tab icon on the main interface or slide the sidebar to enter "Incognito Mode". You can also create a desktop shortcut in the settings. After startup, a prompt will be displayed at the top of the page and the operation will leave no local traces.

You can cast mobile videos to your computer through QQ browser cross-screen traversal, Miracast mirroring or third-party software. First, make sure the device is connected to the same WiFi, use the same QQ account to log in to the QQ browser on both the phone and the computer, click the "Cross-Screen Travel" button on the video playback page and select the target computer to complete the screencasting; if the computer supports Miracast, you can click "Screen Mirroring" in the phone control center to select the computer name to connect; you can also scan the QR code through third-party software such as ApowerMirror to achieve high-definition transmission.