Progressive JPEG Tester
This tool allows you to check if your image is encoded as a progressive JPEG.
Choose the image file to test below:
Result:
FAQ’s
What is a Progressive JPEG?
A progressive JPEG is an image created using compression algorithms that load the image in successive waves until the entire image is downloaded. This makes the image appear to load faster, as it loads the whole image in progressive waves. A standard JPEG loads the image from the top to bottom line by line.
You can read more about Progressive JPEGs here.
What is a Baseline JPEG?
A Baseline JPEG is stored as a top to bottom image that is loaded in one wave.
How does this Progressive Testing Tool work?
This wikipedia article lists some common markers of a JPEG image. Bytes “0xFF, 0xC2” represent the start of frame for a progressive image.
The tool obtains the image binary data using the HTML File API. It then uses JavaScript to search the binary data using regex for that common marker.
If the marker is present, then it is a progressive JPEG.