Reduce JPG file size without losing readable details

Step by step

1. Keep the original image. Choose a JPG, PNG or WebP file in Image Compressor. The output format is a separate setting; select JPEG when your destination needs a .jpg file.
2. Start with quality 75 and maximum width 1920 for a general screen-use comparison. If the destination needs the original dimensions, set maximum width to 0. These are starting settings, not a quality guarantee.
3. Leave target size at 0 and run the tool. Compare the output dimensions and size with your original. Inspect small text, faces and sharp edges at the size you plan to display or print.
4. If a form has a file-size limit, enter a target in KB and rerun from the original. Use a value below the destination's limit when its definition of KB is unclear. Vubilo uses 1 KB = 1,024 bytes.
5. Download the result only after it meets both your size requirement and readability needs. For multiple outputs, download individual files or the ZIP archive.

A worked example

Local test on Windows with Chromium 155. A generated 1200 × 800 image containing colored noise and a text panel was exported as JPEG at quality 95, then compressed from that same original twice.

Input

1200 × 800 JPEG · 909,224 bytes

Without a target

JPEG quality 75 · width 0 · target 0: 468,033 bytes, 1200 × 800 pixels

With a target

JPEG quality 75 · width 0 · target 200 KB: 204,431 bytes, 1200 × 800 pixels

The 200 KB target means 204,800 bytes. This sample met that limit without resizing, but its quality could still change. No visual-equivalence score was measured; inspect your own output for readability. These sizes are not a forecast for photographs.

What the three settings actually change

Quality accepts 10–95 and controls lossy JPEG or WebP encoding. Maximum width accepts 0–12000; 0 keeps the original width, and larger values never upscale a smaller input. Height scales proportionally.

Target size accepts 0–51200 KB. A value of 0 disables target-size fitting. With a target, the tool can lower encoding quality and then shrink dimensions. If it still cannot meet the target, it reports an error instead of labelling the result as successful.

PNG does not use the lossy quality setting in the same way as JPEG. Reaching a smaller PNG target can require reducing dimensions. JPEG also replaces transparent areas with white.

Choose settings for the actual destination

For a website image, use the dimensions required by the layout instead of sending an unnecessarily large photo. For a scanned document, prioritize readable text and check the smallest characters. For a transparent logo, consider PNG or WebP instead of JPEG.

A very small target can remove useful detail. If the result is blurry, increase the allowed size, keep more pixels or ask whether the destination accepts another format. Repeatedly recompressing an already compressed output can introduce further loss; retry from the original.

Batch limits and failures

Use up to 20 files, up to 50 MB per file and 100 MB total, with a decoded limit of 40 million pixels per image. The tool's MB limits use 1,048,576 bytes per MB. Large batches can still exceed the practical memory available on your device.

Check the failed-files list after a batch run. Only successful outputs are downloadable. A file that is already well compressed may not get smaller with your chosen settings; compare the actual bytes rather than assuming every run saves space.

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