Convert PNG, JPEG, WebP, and BMP in the browser
The current DevelopTools image conversion tool accepts PNG, JPEG (JPG), WebP, and BMP input and can convert to PNG, JPEG, WebP, and BMP. It cannot directly load HEIC, HEIF, or AVIF, and does not support AVIF output. Images and conversion results are not sent to a server.
Open the image file conversion toolConclusion: Choose a format based on the image content and destination
JPEG, WebP, and AVIF are candidates for photos, while PNG, WebP, and AVIF are candidates for transparent logos and illustrations. However, AVIF cannot be input or output by the current DevelopTools image conversion tool, so check the destination and conversion method first.
PNG handles lossless compression and alpha channels under the W3C specification. WebP supports lossy and lossless compression and transparency. JPEG is widely used for photographs but cannot retain transparency, and quality may change with every resave.
The optimal choice cannot be determined from the format name alone. Create candidates at the same pixel dimensions and compare actual size and appearance.
Comparison of four formats
| Format | Minify | transparent | Decision guidelines |
|---|---|---|---|
| JPEG | Mainly lossy | Not available | Prioritize photos and compatibility |
| PNG | lossless | Supported | Preserve text, diagrams, and transparency |
| WebP | lossy／lossless | Supported | Compare file size and expression for Web use |
| AVIF | AV1 image encoding | Supported | Check the supported environments before adopting it |
Common failure points when selecting a format
- Converting JPEG to PNG does not restore details lost when the JPEG was saved
- Converting a transparent PNG to JPEG requires compositing it with a background color.
- For a new format, check support not only by its creator but also by the CMS, editing software, distribution destination, and receiver
- If the goal is to reduce file size, try format conversion and pixel-dimension reduction separately
How to convert image formats with DevelopTools
Select or drop images, then choose PNG, JPEG, WebP, or BMP as the output format. For JPEG and WebP, you can set quality; for BMP, choose 24-bit or 32-bit; and, as needed, set maximum width and height, preserve aspect ratio, allow enlargement, rotation, horizontal/vertical flip, and background color. Multiple images can be converted sequentially with the same settings.
Compare dimensions, format, file size, and transparency on screen before saving. When converting to JPEG or 24-bit BMP, transparent areas are composited with the specified background color. PNG, WebP, and 32-bit BMP can handle transparency, but also check display at the destination.
- Duplicate and store the original image, then load a supported PNG, JPEG, WebP, or BMP.
- Choose an output format accepted by the destination, then configure transparency, quality, dimensions, and background color.
- Run conversion, then compare previews, pixel dimensions, and capacity before and after conversion.
- Check text, outlines, gradients, transparent areas, colors, and orientation at 100%, then save under a different name.
Because this Tool draws to Canvas and regenerates the image, it does not retain metadata such as EXIF, GPS, and ICC profiles. Even when animated images can be processed, only the first Frame becomes the result.
Items to check before saving
| Account to check | What to Verify |
|---|---|
| Format | Check not only the extension, but also whether the MIME format of the saved result and the destination's support match. |
| Image quality | Whether text and fine lines blur, photo block noise, and gradation banding are acceptable |
| Transparent areas | Whether the format can preserve transparency and whether it was composited as intended with the background color |
| Dimensions and size | Keep the required pixel dimensions, and check whether an increase over the original is acceptable for the intended use |
| Color and direction | After removing ICC or applying orientation, check whether color, rotation, and flipping are as intended. |
| Original Data | If EXIF, GPS, ICC, or multiple frames are required, check whether the original image is retained |
The relationship between quality value and file size varies by image content, encoder, and browser. There is no fixed conversion such as “quality 90 makes it X% smaller.” Inspect the actual file visually and open it at the destination before deciding.
Reference materials used to verify the specification
Format specifications and application support can change. Prioritize the latest specifications at the destination and the actual file, and retain original files for important images.
Example: choose formats for e-commerce photos and a transparent logo
Duplicate the source image before conversion and check dimensions, transparent areas, colors, orientation, and required metadata. For photos, compare JPEG and WebP; for logos, compare PNG and WebP. Also confirm that the image opens in the actual screen or app where it will be used.
Create multiple versions of the same image using candidate settings, and decide based not only on file size but by comparing text, edges, and photo detail at 100% and at the actual display size.
- Store the original image under a different name.
- Convert using the format and settings appropriate for the intended use.
- Compare dimensions, file size, and appearance before and after conversion.
- Open the files at the destination before deciding which one to use.
Do not overwrite the source image with the conversion result; keep it available for readjustment.
Frequently asked questions
- In Differences between JPEG, PNG, WebP, and AVIF | Choosing image formats by use case, is it okay to change only the extension?
- No. Changing an extension does not change the encoding format inside a file. Load it with a decoder and regenerate it with an encoder for the target format.
- Will conversion always reduce file size?
- No. It may increase depending on image content, pixel dimensions, output format, quality, transparency, and encoder. Compare the actual output size and image quality after conversion.