Size change shown
Δ = T_export ÷ T_source − 1
Negative when the converted file is lighter.
Convert and compress an image
Change an image between PNG, JPEG, and WebP formats, adjust output quality when needed, and download the generated file directly from your browser.
- Export
Image
No image loaded
Drop an image here
Add a PNG, JPEG, or WebP image. The file stays on your device and all edits run locally in your browser.
Need more editing options?
Use multiple editing tools in one workspace, with your open file and its current edits.
Open the full editorProcessing…0 %
Was this tool useful?
How does this tool work?
Every image format has its strengths: PNG for screenshots and transparency, JPEG for photos that open everywhere, WebP and AVIF for lighter web files, BMP and GIF for older software. This converter turns a PNG, JPEG or WebP image into any of these six formats and shows the resulting size before you download, without sending the file online.
Import the image, then choose the Output format: Keep current format, PNG, JPEG, WebP, AVIF, BMP or GIF. The Estimated size comes from actually encoding the image in the chosen format, with the change in percent compared with the original file, and the Dimensions stay those of the image.
PNG is lossless; JPEG and WebP are encoded by the browser at 90% quality. JPEG has no transparency: transparent areas turn white and a warning says so. AVIF, BMP and GIF go through FFmpeg compiled to WebAssembly, downloaded once on first use and then cached; GIF is limited to a 256-colour palette.
The downloaded file keeps the original name followed by -edited and the new extension. Conversion re-encodes the pixels, so EXIF metadata (camera, date, GPS position) is not copied.
How to use this tool
Import the image
Drop a PNG, JPEG or WebP file of up to 25 MB.
Choose the format
Click PNG, JPEG, WebP, AVIF, BMP or GIF and read the estimated size.
Download the converted file
Click Download image to save the new version.
Output size and quality
The estimated size comes from a real encoding; for AVIF, quality is translated into the AV1 codec's CRF factor.
AVIF quality
CRF = round(55 − 40 q)
With q = 0.9, CRF = 19; a lower CRF means better quality and a larger file.
- T_export, T_source
- size of the converted file and of the original file
- q
- quality from 0.2 to 1 (0.9 in this tool)
- CRF
- constant rate factor of the AV1 codec
Use cases
Open a WebP image anywhere
Convert a WebP image saved from a website to PNG or JPEG for software that cannot read it.
Lighten a website's images
Turn JPEG photos into WebP or AVIF and compare the estimated size before choosing.
Meet a format requirement
Provide the JPEG a form demands or the BMP an old program asks for.
Examples
Transparent PNG logo converted to JPEG
JPEG has no alpha channel, so transparency is filled with white (#FFFFFF). Keep PNG or WebP if the logo must sit on a coloured background.
Input
logo.png with a transparent background, output format JPEGResult
logo-edited.jpg on a white backgroundPhoto converted to AVIF
CRF = round(55 − 40 × 0.9) = 19: the lower the CRF, the better the quality. The estimated size lets you compare with WebP before downloading.
Input
photo.jpg, output format AVIF, 90% qualityResult
photo-edited.avif encoded with the AV1 codec at CRF 19Tips and best practices
- For a web photo, compare the estimated size in WebP and AVIF: AVIF is often lighter but slower to encode.
- Do not convert a JPEG photo to PNG to gain quality: the JPEG loss has already happened and the PNG will be much heavier.
- Keep PNG for screenshots with text: JPEG compression creates halos around letters.
- To set the quality or aim for a specific size, use the image optimizer instead.
Sources and references
- Canvas API (opens in a new tab), MDN Web DocsPage in English
Frequently asked questions
Which formats can I produce?
PNG, JPEG, WebP, AVIF, BMP and GIF, or the original format. Imported images must be PNG, JPEG or WebP.
Why does the estimated size sometimes go up?
A lossless format such as PNG or BMP stores every pixel: converting a JPEG photo to PNG often produces a file several times larger.
Why is a connection needed for AVIF, BMP or GIF?
These formats use the FFmpeg module, downloaded on first use from a CDN. Your images themselves are never sent.
Is transparency kept?
Yes in PNG and WebP; GIF only keeps on-or-off transparency; JPEG, BMP and AVIF replace it with white.
Can I set the compression quality?
This tool encodes JPEG and WebP at 90%. To choose the quality or a target size, use the image optimizer.
Is my image uploaded to a server?
No. Decoding and encoding happen in your browser.
Related tools
Keep going with these tools
Tools similar or complementary to this one.
Works well with
Resize an image by setting its exact width and height before downloading the result.
Images & graphicsFeaturedUse this tool
Lighten an image by setting its quality or aiming for a size in KB, with the final size shown before download.
Images & graphicsFeaturedUse this tool
Read next
TutorialBest practicesBeginner
How to Compress an Image Without Unnecessary Quality Loss
Reduce image file size with appropriate dimensions, format, and controlled quality while avoiding unnecessary visible degradation.
31 August 202619 min
GuideFormatsBeginner
PNG, JPEG, WebP, or AVIF: Which Image Format Should You Choose?
Choose the right image format for photos, screenshots, transparent graphics, and interfaces without sacrificing quality or performance unnecessarily.
31 August 202618 min
NewsFormatsIntermediate
WebP, AVIF, JPEG XL: which image formats should you choose in 2026?
WebP, AVIF and JPEG XL have different strengths. Compare compatibility, compression, transparency, HDR and fallback strategies in 2026.
30 August 20264 min
GuideBest practicesBeginner
How to optimize 50 images for the Web at once
Resize a batch of images, convert them to WebP and remove metadata with one reusable Pipeline.
6 September 20262 min