The JPG (JPEG) image format

What it is

JPG, also written JPEG, is named after the Joint Photographic Experts Group, the committee that created the standard in the early 1990s. The extensions .jpg, .jpeg and .jfif all refer to the same format; the three-letter version comes from older systems that only allowed short extensions.

JPG uses lossy compression. The image is split into small blocks, and in each block the encoder discards fine detail and subtle color variation that the human eye is less sensitive to. A quality setting controls how much is discarded. The result is a file many times smaller than the raw pixels, which is why JPG became the standard for digital photos.

Strengths

• Universal support. Every browser, operating system, image editor, phone and upload form handles JPG.
• Small files for photos. At high quality settings, a JPG looks practically identical to the original while taking a fraction of the space.
• Adjustable quality. You choose the balance between file size and detail every time you save.
• Metadata. JPG files can carry EXIF data such as the date, camera settings and location.

Weaknesses

• Lossy. Discarded detail cannot be recovered, and each new save as JPG loses a little more.
• No transparency. Every pixel is opaque, so logos cannot have transparent backgrounds.
• Poor with text and sharp graphics. Hard edges get a faint halo of noise, and flat colors can look blotchy.
• No animation. A JPG holds one still image.
• Older compression. Modern formats such as WebP and AVIF reach similar quality with smaller files.

When to use it

Use JPG for photos you share, email, print or upload to forms, especially when you do not know what software the recipient has. For screenshots, logos and anything with transparency, PNG is the better choice. For photos on your own website, WebP or AVIF usually load faster. The PNG vs JPG guide helps you decide.

How to open and convert JPG

JPG files open everywhere, so the real question is what you want to turn them into.

• JPG to PNG: the JPG to PNG converter creates a lossless copy for editing or systems that require PNG. It will not restore detail and the file usually gets larger.
• JPG to WebP: the WebP converter makes lighter images for websites.
• JPG to AVIF: the AVIF converter produces even smaller files, at the cost of slower encoding.
• JPG to PDF: the image to PDF tool combines several JPGs into one document.
• JPG to ICO: the PNG to ICO converter also accepts JPGs and turns them into icons.
• Smaller JPG: the image compressor reduces file size and keeps the JPG format.

All of these run in your browser, so your photos are not uploaded.