What is JPG?
JPEG (Joint Photographic Experts Group)
JPG is the world's most popular image format, designed for photographs. Its lossy compression delivers small files while keeping photo-realistic quality high — perfect for sharing pictures online and storing camera shots.
History of JPG
JPEG (the format, often called JPG due to old DOS 8.3 filename limits) was standardized in 1992. Its lossy compression algorithm enabled the photographic web — digital cameras, image sharing, and online photo storage all depend on it. Despite being 30+ years old, JPEG remains the dominant photo format.
Technical specs
- Format name
- JPEG (Joint Photographic Experts Group)
- File extension
- .jpg
- MIME type
- image/jpeg
- Category
- Image
- Compression
- Lossy compression
When to use JPG
Reach for JPG when you need digital photography and camera output, sharing photos on social media, web images and product photography, email attachments. It excels at these scenarios because universal device and browser support and excellent compression for photos.
Pros
- +Universal device and browser support
- +Excellent compression for photos
- +Very small file sizes
When to avoid JPG
Avoid JPG when lossy — quality degrades each time you re-save, and no transparency support. In those cases, look at the alternatives below.
Cons
- −Lossy — quality degrades each time you re-save
- −No transparency support
- −Poor for graphics, logos and line art
Common uses for JPG
- Digital photography and camera output
- Sharing photos on social media
- Web images and product photography
- Email attachments
Alternatives to JPG
For lossless quality with transparency, use PNG. For modern web optimization, WebP or AVIF.
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JPG — Frequently Asked Questions
Is JPG still used in 2026?
Is JPG still used in 2026?
Yes, JPG is actively used. Digital photography and camera output keeps it relevant.
Can I open a JPG file on my phone?
Can I open a JPG file on my phone?
Yes, on every phone.
Why is my JPG file so small?
Why is my JPG file so small?
JPG files are usually compact because the format uses efficient compression. If yours feels unusually large, the encoder may have been set to a high bitrate / quality setting.
Can I convert JPG to another format for free?
Can I convert JPG to another format for free?
Yes — Zen Convert converts JPG files to every other image format we support, for free, in your browser. No signup, no watermark.
Is JPG open-source?
Is JPG open-source?
JPEG is openly documented and royalty-free in practice — patents have all expired.