With so many image formats available, choosing the right one can feel confusing. Should you save your photo as JPG, export your logo as PNG, or switch everything to WebP? The answer depends on what the image contains, where it will be used, and how much file size matters. This guide breaks down the three most common web image formats so you can make the right choice every time.
JPG (JPEG) — The Standard for Photographs
JPG has been the default image format on the web since the 1990s. It uses lossy compression, which means it permanently removes some image data to achieve smaller files. The compression algorithm is particularly good at handling smooth gradients, complex colour transitions, and the kind of detail found in real-world photographs.
When to Use JPG
- Photographs and realistic images with millions of colours.
- Social media uploads, blog post featured images, and product photos.
- Any situation where file size matters more than pixel-perfect precision.
When to Avoid JPG
- Images with text, sharp lines, or flat-colour areas — JPG creates visible artefacts around hard edges.
- Images that need transparency — JPG does not support transparent backgrounds.
- Images you plan to edit and re-save multiple times — quality degrades with each save cycle.
PNG — The Choice for Graphics and Transparency
PNG uses lossless compression, meaning no data is lost when you save. The file you open is pixel-for-pixel identical to the file you saved. PNG also supports alpha transparency — pixels can be fully transparent, fully opaque, or anything in between.
When to Use PNG
- Logos, icons, and illustrations with flat colours and sharp edges.
- Screenshots containing text — PNG preserves text sharpness perfectly.
- Any image that requires a transparent background (overlays, watermarks, UI elements).
- Working files that you will edit again later — no quality loss on re-save.
When to Avoid PNG
- Large photographs — a PNG photo can be 5–10 times larger than the same image saved as JPG with minimal visible difference.
- Web pages where loading speed is critical — PNG files are heavier, which slows page load times.
WebP — The Modern All-Rounder
Developed by Google, WebP supports both lossy and lossless compression, transparency, and even animation. It consistently produces smaller files than both JPG and PNG at equivalent visual quality — typically 25–35% smaller than JPG and 25% smaller than lossless PNG.
When to Use WebP
- Any web image where you want the best balance of quality and file size.
- Sites targeting modern browsers — Chrome, Firefox, Safari, and Edge all support WebP as of 2023.
- Replacing both JPG and PNG with a single format to simplify your workflow.
When to Avoid WebP
- Email newsletters — many email clients do not render WebP images.
- Print workflows — most print software expects TIFF, PNG, or JPG.
- Apps or platforms that explicitly require JPG or PNG uploads.
Side-by-Side Comparison
| Feature | JPG | PNG | WebP |
|---|---|---|---|
| Compression | Lossy | Lossless | Both |
| Transparency | No | Yes | Yes |
| Animation | No | No | Yes |
| File size (photo) | Small | Large | Smallest |
| Best for | Photos | Graphics | Everything |
| Browser support | Universal | Universal | Modern |
How to Convert Between Formats
If you already have an image in one format and need another, you do not need Photoshop. Browser-based tools can convert instantly. Rekreay's free Image Format Converter lets you upload a JPG, PNG, or WebP file and download it in any of the other formats — entirely in your browser with no upload to any server.
You can also resize during conversion if needed. Use Rekreay's Image Resizer to set exact dimensions, then choose your preferred output format before downloading.
The Simple Decision Rule
If you are unsure which format to use, follow this quick rule:
- Is it a photograph? → Use JPG (or WebP for better compression).
- Does it need transparency? → Use PNG (or WebP).
- Is it for a modern website? → Use WebP for everything.
- Is it for email or print? → Stick with JPG or PNG.
Final Thoughts
There is no single "best" image format — each serves a different purpose. JPG remains the reliable choice for photographs, PNG is essential for graphics and transparency, and WebP is the smart default for modern web projects. Understanding when to use each format gives you smaller files, faster pages, and better-looking images — without any compromise.