JPG, PNG and WebP all store raster images, but they make different trade-offs between compression, transparency, compatibility and file size. Instead of asking which format is universally best, choose the format that fits the image and the destination.
JPG: a practical choice for photographs
JPG (JPEG) commonly uses lossy compression and is well suited to photographs and other continuous-tone images. It can produce relatively small files, especially when some visual information can be discarded. It does not support transparency.
PNG: useful for graphics and transparency
PNG uses lossless compression and supports transparency. It is often a good choice for screenshots, diagrams, logos, interface graphics and images with sharp edges or text. The same properties can make PNG inefficient for large photographs.
WebP: flexible web delivery
WebP supports lossy and lossless compression and transparency. It can be an efficient web-delivery format when the destination supports it. Actual file size depends on the source image and encoding settings.
Quick comparison
| Need | Typical choice | Why |
|---|---|---|
| Photograph | JPG or WebP | Efficient compression |
| Screenshot with text | PNG or WebP | Sharp edges and text |
| Transparency | PNG or WebP | Supports transparent pixels |
| Broad legacy compatibility | JPG or PNG | Widely supported |
| Modern website delivery | WebP or another supported modern format | Often efficient |
Choose based on the image, not the extension
The same format can work well for one image and poorly for another. A photograph can compress efficiently as JPG, while a screenshot with tiny text may look worse at the same file size. Test the actual image instead of applying one format rule to every asset.
What about quality?
Lossy compression can reduce file size by discarding information. Lossless formats keep the current pixel information but may require more storage for complex images. If the image contains small text or critical details, inspect the output at the target display size.
What about transparency?
JPG cannot retain transparency. PNG and WebP can. If an asset must appear over different backgrounds, keep a transparency-capable format.
What about website performance?
Smaller images can reduce transfer size, but performance is not determined by file format alone. Dimensions, compression level, responsive image delivery and how the page loads images also matter. Avoid chasing a format change when the real problem is an oversized image.
Use Tervilo tools to test the choice
You can compare the same asset with Tervilo's Image Compressor and Image Converter. The useful result is the version that meets the destination's format requirements and remains visually acceptable.
Common mistakes
- Assuming PNG is always higher quality in a useful sense.
- Using JPG for an asset that requires transparency.
- Choosing a format without checking the destination's support.
- Judging performance by extension alone.
- Optimizing file size before checking pixel dimensions.
Quick checklist
- □ I identified whether the image is a photo, graphic or screenshot.
- □ I checked whether transparency is required.
- □ I checked destination compatibility.
- □ I compared actual file size and visual quality.
- □ I verified dimensions separately from format.
Quick answer
Use JPG for many photographs, PNG for lossless graphics and transparency, and WebP when modern web delivery and supported compatibility make it a good fit. The right format depends on the actual image and destination, so compare the output rather than following a universal rule.