Why does my JPG have a white background when my PNG had transparency?

JPEG does not support an alpha channel, so transparent areas are replaced with a solid color. In Photoshop, the background color (usually white) is used. In GIMP, you must flatten the image first to fill transparency with the background color.

What is the difference between the quality scales in Photoshop and GIMP?

Photoshop's Save a Copy dialog uses a 0 to 12 scale, where 12 is best quality. Photoshop's Export As uses a 0 to 100 percentage. GIMP uses a 0 to 100 slider. A value of 80-90 on the percentage scales corresponds roughly to 10-11 on Photoshop's 0-12 scale.

Can I keep layers when I convert to JPG?

No. The JPEG format does not support layers or transparency. Both Photoshop and GIMP flatten the image during export. If you need to keep layers, save a copy in the native format (PSD or XCF) before exporting to JPG.

Which format option should I choose in Photoshop's JPEG Options (Baseline, Baseline Optimized, or Progressive)?

Baseline is the most compatible choice and works everywhere. Baseline Optimized gives slightly smaller file sizes with the same quality. Progressive loads the image in multiple passes and is useful for slow internet connections, but some older software may not support it.

Convert PNG to JPG in Photoshop and GIMP

Converting a PNG to a JPG in Photoshop or GIMP is simple once you know the correct menu paths and compression settings. The two editors handle transparency differently and use different scales for JPEG compression. Here is the step-by-step for each application, so you can export a JPG from your existing PNG file without guesswork.

Convert PNG to JPG in Photoshop

Photoshop gives you two routes to a JPG from a PNG. Both live in the File menu, but they use different dialog boxes and compression scales. Pick the one that fits your workflow.

Method 1 Save a Copy

Classic JPEG Options Dialog

This method gives you a classic JPEG Options dialog with a compression scale from 0 to 12. It is the fastest route if you already have your PNG open.

Open your PNG file in Photoshop.
Go to File > Save a Copy. On Windows, the shortcut is Alt+Ctrl+S; on Mac it is Option+Cmd+S.
In the Save As dialog, choose JPEG from the Format dropdown.
Click Save. The JPEG Options dialog appears.
Set the compression value (0 to 12). A high value gives high fidelity with a reasonable file size. Values below 6 show visible artifacts.
Choose a Format option: Baseline (widest compatibility), Baseline Optimized (slightly better compression), or Progressive (loads in multiple passes in older browsers).
Click OK to save the JPG.

The dialog also shows a small preview and an estimated file size. If your PNG has transparent areas, they will be filled with white (or the current background color) because JPEG does not support an alpha channel.

Method 2 Export as

Percentage-Based Export Dialog

The Export As dialog uses a percentage instead of the 0-12 scale. This is more intuitive if you are used to percentage-based sliders.

Open your PNG in Photoshop.
Go to File > Export > Export As. The shortcut is Alt+Shift+Ctrl+W on Windows or Option+Shift+Cmd+W on Mac.
In the dialog, choose JPG from the Format dropdown.
Set the percentage. A high value balances size and visible fidelity for photos.
Check the Convert to sRGB option if you are preparing the image for web use.
Click Export and choose a destination.

This method also flattens transparency automatically, replacing it with the background color you see on the canvas.

Convert PNG to JPG in GIMP

GIMP works differently from Photoshop. Its native save function only writes XCF files, so you must use Export to create a JPG. The process is straightforward and uses a compression slider from 0 to 100.

Export a PNG as JPG in GIMP

Step-by-Step Export

Follow these steps to export your PNG as a JPG in GIMP:

Open your PNG file in GIMP.
Go to File > Export As (shortcut Shift+Ctrl+E).
In the Export Image dialog, type a file name ending in .jpg (for example, photo.jpg).
Click Export. The Export Image as JPEG dialog opens.
Use the slider to set the compression level. The scale runs from 0 (maximum compression, lowest fidelity) to 100 (minimum compression, highest fidelity). A high value is a common balance between file size and visible results for photos.
Under Advanced Options, you can adjust subsampling and smoothing if needed. The default settings work well for most images.
Click Export to save the JPG.

If your PNG has transparent areas, you must flatten them before exporting to avoid unexpected results. GIMP does not automatically fill transparency when you export to JPEG.

Handling Transparency in GIMP

Flatten the Image

Because the JPEG format does not support an alpha channel, any transparent areas in your PNG must be filled with a solid color before exporting. GIMP gives you control over this step. To fill transparent areas with the current background color, go to Image > Flatten Image. This merges all layers and replaces transparency with the background color (usually white, unless you changed it).

Set the Background Color

Before flattening, set the background color to what you want the transparent areas to become. The background color is shown in the Toolbox. Click it to open the color picker and choose a color (e.g., white, black, or a specific hex value). Then flatten the image.

Skipping flattening means transparent pixels may export as black or produce artifacts in the JPG. Always flatten before exporting to JPG.

Which Compression Setting Should You Use?

Settings for Each Editor

The right compression setting depends on your image and its intended use.

Photoshop (0-12 scale): High values produce high fidelity with a small file size. The maximum is lossless (within JPEG limits) but creates larger files. Values below 6 are usable for thumbnails or previews.
Photoshop Export As (percentage): A high percentage is a common balance between size and visible results for photos. The maximum gives the best fidelity but a much larger file.
GIMP (0-100 scale): A high value is the same common balance. Below a certain point, compression artifacts become noticeable on most images.

Choosing for Your Use Case

For web use, start with a high value (or a high value on the Photoshop 0-12 scale) and adjust downward if the file size is too large. For archival or printing, use the highest setting that keeps the file size manageable.