Compress JPG
Re-encode JPG photos in your browser and compare the original with the result.
JPG compression involves a choice between file size and image quality. The button on this page selects JPG and high quality mode. After you select a photo, encoding runs in a worker.
High quality mode searches for an SSIM of at least 0.985 using comparison images with a longest side of up to 512 pixels. A notice appears if the threshold is not reached. A high score does not mean every detail is identical.
Switch to target size mode for a specific KB limit, or custom mode to adjust quality yourself. An already efficient JPG can become larger after re-encoding, so check the actual result.
How to use
- Select a JPG photo.
- Start with JPG and high quality mode, or enter a target in KB.
- Compare the image and file size, then download.
Tip
Compare settings using the original rather than repeatedly compressing a downloaded result. If the result grows, also consider the original format setting.
Frequently asked questions
Are JPG and JPEG different formats?
They refer to the same JPEG format in this tool. Selecting JPG produces a file with a .jpg extension.
Will the compressed photo be identical?
JPG uses lossy compression. High quality mode aims for the SSIM threshold but does not guarantee identical pixels.
Can a JPG become larger?
Yes. Selecting JPG explicitly re-encodes the image. With original format selected, the tool keeps the source if there are no dimension or refinement changes and the result is not smaller.
Are iPhone HEIC/HEIF photos supported?
Yes. The first image in a HEIC/HEIF file is decoded in your browser. Keep original format saves it as JPG. If decoding fails, convert the photo to JPG and try again.