Adjust Colors/Contrast
Enhance PDF appearance with color, brightness, and contrast adjustments.
Drag & drop files here, or click to select
Color Adjustments
Effects
How to Adjust PDF Colors and Contrast Online
Select the PDF document from your device.
Adjust parameters such as brightness level, contrast ratio, and color balance.
Choose the page range to apply the color changes to.
Click the Adjust Colors button to process and save.
Why Use SonuPDF to Adjust Colors?
In-Browser Color Tuning
Adjustments are processed locally within your web browser. In contrast to other services, your documents are never uploaded to a cloud server.
Fine-grained Slider Control
Precision sliders for brightness, contrast, hue, saturation, and lightness to restore faint text or adjust scans.
Selective Page Tuning
Target only specific pages that need refinement or apply color adjustments to the entire document.
Responsive Page Preview
See changes reflected in the page viewer immediately as you slide the controls.
Frequently Asked Questions
Processing runs client-side in the browser. Your file stays inside your computer's local memory, meaning zero risk of server data leaks.
Yes, increasing the contrast and adjusting brightness can significantly enhance faded or low-contrast text in scanned pages.
The tool supports standard rgb color transformations, allowing grayscale conversion, color inversion, and general brightness tuning.
Generally no. Color adjustments are calculated and applied directly to page rendering properties, which preserves the original file structure without adding heavy data.