Diagnostic Tool

Interactive Troubleshooter

Follow the wizard below to diagnose and resolve the most common issues you might experience in the Leef Browser.

What's the main problem?
I'm having trouble downloading, installing, or updating the browser
A specific website isn't loading or looks broken
Search & Privacy troubleshooting
Video player & audio troubleshooting
Performance troubleshooting
Something else / Other error screens
What specific installation or update issue are you encountering?
The in-app automatic updater isn't working
The installer says Leef is already open
Windows SmartScreen ("Windows protected your PC") is blocking me
macOS says it can't open Leef because it's from an unidentified developer
What search or privacy feature are you trying to configure?
Sometimes I google something and it redirects me to DuckDuckGo
I want to clear my browsing data or start fresh (reset settings)
Address bar search suggestions aren't appearing as I type
What kind of media issue are you experiencing?
YouTube or videos behave strangely
Music or audio stops in the background
Which category does the issue fall into?
Memory/CPU usage is too high
Visual glitches, flickering, or black/white screens
Network errors (ERR_CONNECTION_...)
Websites show security certificate warnings (SSL errors)
The browser keeps crashing or won't open
What does the loading issue look like?
The site has missing elements, broken layout, or blocks access
I see an SSL security certificate warning (e.g., date/time error)
I see a connection/network error page (e.g., ERR_CONNECTION_RESET)
Are you using "Comprehensive" ad-blocking?
Yes, it's set to Comprehensive
No, I'm using Basic or None
What exactly is happening on YouTube?
The video won't play / Ad-blocker detected
The video is playing at crazy fast speed
Does it happen when you switch to another tab?
Yes, it stops when I leave the tab
No, it just stops randomly
Do you usually have many tabs open at once?
Yes, I'm a tab hoarder
No, just a few
Suggested Solution: Dial it back

Comprehensive blocking can sometimes be too aggressive and break site layouts. Try switching to Basic blocking or disabling it entirely via Settings > Privacy & Security.

If this doesn't fix it, we're very happy to help personally! Please report the issue so we can improve Leef.

Suggested Solution: Check Recovery Mode

If the site is broken even with basic blocking, an internal component might be stuck. Try launching in Recovery Mode and selecting Reset Window or Reset Config.

Still broken? We want to hear about it. Please reach out and we'll help you get it sorted.

Suggested Solution: Disable Ad-blocking for YouTube

YouTube has recently started aggressively blocking ad-blockers. To watch videos, you may need to disable Leef's ad-blocker entirely via Settings > Privacy & Security. We are working on a more permanent fix!

Not working? Please let us know. We track these changes closely to keep Leef compatible.

Suggested Solution: Disable "Warp Speed" Lab

You likely enabled YouTube Warp Speed in leef://labs. This skips unskippable ads by playing them at 16x speed, but it can sometimes get stuck on the main video. Try toggling it off.

Suggested Solution: Disable Background Limit

In Settings > Privacy & Security, make sure "Background Limit" is toggled OFF. When enabled, Leef pauses all background audio and video to save resources.

Still stopping? We're happy to investigate. Open a ticket or email us!

Suggested Solution: Check Efficiency Mode

Efficiency Mode throttles background tabs to 30% CPU. If your audio stream is high quality, this can cause stuttering. Try disabling Efficiency Mode in Settings > Performance.

If it's still stuttering, we want to know. Help us tune our performance by reporting it.

Suggested Solution: Enable Efficiency Mode

If you have many tabs, Efficiency Mode is your best friend. It throttles background tabs to save RAM and CPU. Enable it in Settings > Performance.

Browser still slow? We're happy to help you diagnose it. Please contact us.

Suggested Solution: Rebuild AppData

If the browser is slow with only a few tabs, there might be corrupted data. Try the Rebuild AppData option in Recovery Mode (hold Shift at launch).

No luck? We're very happy to help personally. Please open a bug report.

Suggested Solution: Toggle Hardware Acceleration / GPU Settings

Visual glitches, black/white windows, or flickering are usually caused by conflicts with the GPU process. Try launching Leef from your terminal/command line with the --disable-gpu flag. If the window displays correctly, go to Settings > Performance and disable Hardware Acceleration.

Alternatively, you can launch in Recovery Mode (hold Shift at launch) and select Reset Window Layout to reset corrupt graphic states.

Suggested Solution: Check Connection & DNS

Network errors like ERR_CONNECTION_RESET are usually external. Try restarting your router or checking your firewall. See more in Other Issues.

Can't connect? We're happy to help you troubleshoot. Please get in touch.

Suggested Solution: Use Recovery Mode

For persistent crashes or startup failures, Recovery Mode is the best tool to reset your configuration without losing data.

Still crashing? We're very happy to help you fix it! Please report the crash.

Suggested Solution: Reset & Re-run Setup

You can re-trigger the first-launch experience or clear all local browsing data at any time by going to Settings > Privacy & Security and using the Re-run Setup Wizard or Clear Browser Data buttons.

Need a deep clean? You can also launch in Recovery Mode (Hold Shift at launch) and select rebuild appdata.

Suggested Solution: Download Direct Update

If the in-app automatic updater fails to download or apply a new version, you can always download and run the latest installer directly from the official Leef GitHub Releases page.

Suggested Solution: Use OS-Native Version

This error is a known bug that occurs when trying to run the Windows version of Leef via compatibility/emulation layers (like Wine or Proton) on macOS or Linux. Please make sure you have downloaded and installed the correct native build built for your specific operating system (e.g. macOS .dmg/.pkg or Linux package).

Suggested Solution: Bypass Windows SmartScreen

Because Leef is a newly released, open-source project, Windows Defender SmartScreen might display a message saying "Windows protected your PC". To finish installation, click the More Info link on that screen, and then select the Run Anyway button that appears.

Suggested Solution: Allow Installation in macOS Settings

To open Leef on macOS for the first time, you must right-click (or Control-click) the application icon and select Open from the context menu. If you double-clicked it and got blocked by Gatekeeper, open the macOS System Settings app, navigate to Privacy & Security, scroll down to the Security section, and click the button to allow Leef to open.

Suggested Solution: Enable Live Autocomplete

To maximize your privacy, Leef disables search queries autocomplete by default so that nothing is sent to search engines as you type. If you prefer live search suggestions, you can turn this option on by going to Settings > Privacy & Security and toggling ON the Live Autocomplete setting.

Suggested Solution: Check System Date & Time

Chromium requires highly accurate system time to establish secure HTTPS connections. If your computer's system clock is off by even a few minutes, security handshakes will fail and show certificate warnings. Go to your operating system's settings and verify that your date, time, and timezone are set to synchronize automatically.

Suggested Solution: Automatic Search Engine Fallback

This is expected behavior! Google is currently changing their search engine frequently, so some things may break with certain searches. To ensure you can always find what you're looking for, if a Google search fails, Leef automatically falls back to DuckDuckGo.