PJHTech Images

Why does text look blurry in an image?

Start by viewing the original at one image pixel per display pixel. If the letters are already unclear there, changing the file extension will not restore them.

Text and compression

Original test graphic with text and fine colored lines.
Source PNG
Download original file
Same graphic exported as a quality-30 JPEG.
JPEG: quality 30, 4:2:0
Download original file
Same graphic exported as a quality-90 JPEG.
JPEG: quality 90, 4:4:4
Download original file

Look for speckles around letters and blurred colored edges in the quality-30 JPEG. Both JPEG quality and color sampling differ here; this is not a quality-only comparison. Open the full-size views to see the differences.

Compare at full size

Source PNG

Original test graphic with text and fine colored lines.

JPEG: quality 30, 4:2:0

Same graphic exported as a quality-30 JPEG.

JPEG: quality 90, 4:4:4

Same graphic exported as a quality-90 JPEG.
Settings and measurements
FileDimensionsBytesExport settings
text-source.png1024 × 51222,860Optimize: True
text-jpeg-q30.jpg1024 × 51219,828Quality: 30, Subsampling: 2, Optimize: True
text-jpeg-q90.jpg1024 × 51257,293Quality: 90, Subsampling: 0, Optimize: True

Python 3.14.4, Pillow 13.0.0, Platform Linux, Webp 1.6.0, Jpeg 6.2, Avif 1.4.2

Find the stage that changed it

  1. Compare the original capture with the exported file. If only the export is damaged, change its settings.
  2. Check the pixel dimensions. A smaller export may have discarded detail.
  3. Check the displayed size. Enlarging a small image spreads its existing detail over more space.
  4. For a new text-heavy capture, try a lossless export and compare it with the original.

Browser zoom and high-density screens can make a casual screenshot comparison misleading. Use the supplied original downloads when inspecting our example.

Related guides

Sources