How to Convert Bulky PNG Images to Lightweight JPG Files

Screenshots captured on high resolution retina displays or modern laptops are saved as PNG files that can be several megabytes each. Converting them to JPG usually makes them much smaller.

How transparency is handled

The JPEG standard does not support transparent alpha channels. When a PNG with a transparent background is converted into a JPG, transparent pixels are automatically rendered against a clean white backdrop.

How to convert PNG to JPG

1. Select one or multiple PNG screenshots.
2. Set the quality slider. At 90 the difference from the original is very hard to see.
3. Press Convert to JPG.
4. Download your lightweight images individually or as a single ZIP archive.

Smaller files are quicker to attach, send and upload.

Worked example: emailing six screenshots to support

You are reporting a problem to a software company and have six full screen captures. Together they exceed the attachment limit of the support form.

1. Before converting, crop each screenshot to the window or message that matters. This removes most of the pixels and protects your privacy, since the rest of your desktop is no longer visible.
2. Select all six PNG files in the converter and set the quality to 90, because the error messages must stay readable.
3. Convert and download everything as one ZIP file, or attach the six JPG files separately if the form does not take ZIP files.
4. Open one of the JPG files and read the smallest text in it before you send.

Common mistakes

• Sending uncropped screenshots. Besides the size, they often show browser tabs, notifications and file names you did not mean to share.
• Choosing a low quality for screenshots of text. Support staff cannot help if they cannot read the error code.
• Converting logos and diagrams. Flat graphics often stay smaller and cleaner as PNG.
• Deleting the PNG files straight away. If someone asks for a clearer copy, you will want them.
• Converting a picture with a transparent background and being surprised by the white fill.

Choosing between JPG and a smaller PNG

JPG is not the only way to shrink a screenshot. If the capture is mostly flat interface with little photographic content, cropping and reducing its width may bring the PNG under the limit while keeping the text perfect. A simple test: convert once and compare. If the JPG is not at least half the size of the PNG, the picture is probably better left as PNG and made smaller in pixels instead.

Troubleshooting

• The form still says the file is too large: check whether the limit applies to each file or to all attachments together.
• Colours look slightly washed out: screenshots from wide colour displays can shift a little in conversion. For support and forms this does not matter. For design work, keep the PNG.
• A ZIP file is refused: attach the JPG files one by one.

Checklist

• Each screenshot is cropped to what matters.
• Nothing private is visible.
• The text is readable in the JPG.
• The total size is under the limit.