Help & Instructions
Get started quickly and enable PDF Dark Mode everywhere.
Quick Start
- Install PDF Dark Mode from your browser extension store.
- Open any PDF in your browser.
- Use the extension popup to toggle dark mode and adjust reading settings.
Read PDFs on the Website
You can also open any PDF directly at pdf-dark.com/reader.html — no install needed. Files are rendered locally in your browser and never uploaded. Use Prev/Next or type a page number, zoom or fit-width, and tune Darkness and Contrast.
Enable for Local PDF Files
To apply dark mode to PDFs opened from your computer (file:// URLs), enable file access:
- Open your browser's Extensions page.
- Click Manage extensions.
- Find PDF Dark Mode and open Details.
- Turn on Allow access to file URLs.
Tip: If local PDFs still appear unchanged, refresh the PDF tab after enabling file access.
Troubleshooting
- Make sure the extension is enabled in your browser.
- Check if the website or PDF source is blocked by per-site rules.
- Reload the PDF page after changing extension settings.
- Try disabling other PDF-related extensions to avoid conflicts.
Pro License Validation Policy
- Pro access is activated using a Lemon Squeezy license key.
- License status is validated automatically in the background (no manual validate step in popup).
- Validation is throttled to periodic checks (about every 24 hours), not on every popup open.
- Stale-while-revalidate behavior is used: if a previously active license is stored locally, Pro remains available while background validation runs.
- If Lemon Squeezy reports the license as invalid or inactive (for example after a refund or chargeback), Pro access is removed on the next successful validation.
Need More Help?
Reach us through the links below: