Image decisions explained
JPG vs PNG vs WebP: which format should you choose?
Choose a format according to the image, the destination and the features you need—not from a rule that ignores transparency, compatibility or file size.
The quick answer
Use JPG when broad compatibility matters and the image is a photograph without transparency. Use PNG when you need transparency, pixel-sharp interface graphics or a lossless working file. Use WebP for modern websites and apps when smaller delivery files matter.
That answer is a starting point, not a verdict. A simple logo can be smaller as PNG, while a large photograph will usually be dramatically lighter as JPG or WebP. Test the actual image when file size matters.
What actually changes between the formats?
JPG discards selected image detail
JPG uses lossy compression. It is efficient for photographs because it simplifies subtle colour and brightness information that is expensive to store. Repeated exports can create blockiness, halos and muddy fine texture. JPG cannot preserve transparent pixels.
PNG preserves pixel information
PNG is lossless. It is excellent for logos, screenshots, diagrams and graphics with transparency, but photographs often become much larger. A quality slider does not compress PNG in the same way as JPG because PNG does not use that lossy quality setting.
WebP supports modern compression and transparency
WebP can be lossy or lossless and supports transparency. For many photographs and web graphics it produces a smaller file than JPG at a practical setting. Current browsers support it well, but an older workflow, document system or upload portal may still demand JPG or PNG.
Decision table
| Situation | Start with | Why | Check |
|---|---|---|---|
| Photograph for a website | WebP | Usually strong size-to-quality balance | Visual texture and CMS support |
| Photo for a form | JPG | Commonly accepted | Exact KB and pixel limits |
| Logo with transparency | PNG or WebP | Both can preserve transparency | Destination support and real size |
| Screenshot with text | PNG | Keeps hard edges clean | File size; WebP may still win |
| Email attachment | JPG | Compatible and easy to reduce | Dimensions are not excessive |
| Product image | WebP | Fast delivery on modern sites | Fallback requirements |
Three examples where the winner changes
A phone photograph
PNG stores the photographic noise and colour variation precisely, so it can become several times larger. JPG and WebP are the sensible candidates.
A transparent icon
JPG fills transparency with a colour. PNG may remain tiny for a limited palette; WebP is worth testing when the icon is complex.
A screenshot
PNG protects small text and sharp UI edges. A lossy format can still work, but inspect labels and fine lines rather than judging only the overall preview.
Mistakes that create worse files
- Changing only the extension: renaming
.pngto.jpgdoes not convert the image. - Exporting a small JPG repeatedly: each lossy generation can add damage.
- Choosing PNG because it sounds higher quality: lossless is valuable, but unnecessary for many delivery photographs.
- Ignoring pixel dimensions: a 6000-pixel image can stay heavy in every format.
- Assuming the smallest file is automatically best: transparency, compatibility and visible detail still matter.
Questions people often ask
Is WebP always smaller than JPG?
No. It often is, but encoder implementation, quality, image content and metadata all influence the result. Compare the same image at a similar practical setting.
Does converting JPG to PNG restore quality?
No. PNG prevents further lossy encoding, but it cannot reconstruct detail already discarded by the JPG.
Which format is best for Google?
Search visibility does not come from a single format. Use an appropriately sized image that renders correctly, loads quickly and can be understood in the page context.
Check it with real data
Test your own image in all three formats
The lab keeps the same dimensions, compares real file size and creates three downloadable files without uploading the image.
Open the optimization lab