PDF enhancer

How to enhance a PDF

1. Pick a starting point above. Balanced is selected to begin with and measures each page.
2. Choose your PDF, or drop it on the page. It is processed in your browser and never uploaded.
3. Drag the slider to compare the original with the result, and use Previous and Next to check other pages.
4. If it is not right, change the starting point or move a slider, then press Apply new settings.
5. Download the new PDF. The original is left untouched.

What the enhancer can change

• Text darkness — pushes faint ink towards black.
• Contrast — widens the gap between ink and paper.
• Brightness — lifts or lowers the mid-tones without moving pure black or white.
• Background — pushes grey paper towards white, using a paper level measured across the page.
• Sharpening — a mild unsharp mask that firms up soft edges.
• Noise reduction — removes speckle from the paper side of the page without touching the strokes.
• Under Advanced settings you can also switch to Grayscale or Black & White, keep or drop colour, and turn Thicken thin text on or off.

Which tool for which problem

The enhancer does all of the above at once. If you already know what is wrong, a focused page starts in the right place:

• The page looks grey and dull: Brighten PDF.
• The text is faint or faded: Darken PDF or Fix a faded PDF.
• The page looks flat: PDF contrast enhancer.
• It prints too light: PDF print optimizer, which measures first and recommends settings.
• It is a scan with shadows, speckle or a grey cast: Enhance a scanned PDF or Clean a scanned PDF.

The four starting points

• Balanced — measures each page and applies only what it needs. A page that is already crisp is left almost alone.
• Scan cleanup — strong background correction and despeckling with moderate darkening.
• Print ready — darker ink, whiter paper and a mild sharpen, tuned for paper.
• Lift dull pages — lifts mid-tones and whitens dull paper while keeping the ink solid.
• Move any slider and the starting point shows as Custom. Your numbers are used exactly as set.

What enhancing cannot do

• It cannot add resolution. A low-resolution scan stays low resolution; sharpening only improves how crisp the existing detail looks.
• It cannot recover detail that was never captured, such as a stroke that has faded to exactly the colour of the paper.
• It does not straighten crooked pages or edit text, and it does not run OCR here: OCR a scanned PDF cleans and reads a scan.
• It does not use AI. The result is a measured tone correction, which is why you can predict and adjust it.