What is JPG?
JPG (also written as JPEG) is the world's most widely used image format. It uses lossy compression, permanently discarding some visual data to achieve dramatically smaller file sizes. The clever part is that the data JPG discards is the least noticeable to the human eye, so a well-compressed JPG can look nearly identical to the original while being 5–20× smaller.
JPG is the dominant format for photographs because real-world scenes contain gradual colour transitions that compress extremely efficiently. A 10 MB camera photo might become a 600 KB JPG with no visible degradation at typical screen sizes.
What is PNG?
PNG (Portable Network Graphics) was created as an open, free format. Unlike JPG, PNG uses lossless compression — it reduces file size without ever discarding pixel data. Every time you save a PNG, it is byte-for-byte identical to the original.
PNG's killer feature is alpha channel transparency. Each pixel can be fully opaque, fully transparent, or anywhere in between. This makes PNG the go-to format for logos, icons, and UI elements that need to sit on different backgrounds.
Key Differences
| Feature | JPG | PNG |
|---|---|---|
| Compression type | Lossy | Lossless |
| Transparency support | No | Yes (alpha channel) |
| File size | Smaller (5–20×) | Larger |
| Best for | Photographs | Logos, icons, graphics |
| Re-save quality loss | Yes | No |
| Browser support | Universal | Universal |
When to Use JPG
- Photographs and realistic imagery — Real-world scenes with smooth colour gradients compress beautifully.
- Social media uploads — Most platforms re-compress uploads anyway; starting with JPG keeps file sizes manageable.
- Web background images — Full-width hero images should be JPGs for faster page load times.
- Email attachments — When you need to send photos without huge file sizes, JPG is the right choice.
When to Use PNG
- Logos and brand assets — Logos need crisp edges and transparent backgrounds. PNG is the only choice.
- Images with text — Text in JPG becomes blurry due to compression artifacts. PNG keeps text razor-sharp.
- Images you will continue editing — Work in PNG to avoid accumulation of quality loss from repeated saves.
- Screenshots — Screenshots contain sharp edges and solid colours that PNG handles much better than JPG.
The Re-Save Problem
Each time you open a JPG, make a change, and save it again, the compression algorithm runs again — discarding more data each time. After just a handful of edit-save cycles, visible quality degradation appears. This is why professional workflows use PNG as the working format and only export to JPG at the very end.
Quick Decision Guide
📸 Is it a photograph? → Use JPG
🎨 Does it need a transparent background? → Use PNG
✏️ Does it contain text or sharp lines? → Use PNG
💾 Will you keep editing it? → Use PNG, export JPG at the end
🌐 Is it a hero/background for a website? → Use JPG
Convert Between Formats
Need to switch formats? FileNexa makes it free and instant — all processing runs locally in your browser, so your files never get uploaded anywhere.