Should you save that signature as PNG or JPG? Why is your screenshot 2 MB as a PNG but 200 KB as a JPG? Why does a logo look fuzzy around the edges after converting? PNG and JPG are the two most common image formats, and each is good at different things. Choosing the wrong one gives you blurry text, huge files or rejected uploads. This guide explains the difference in practical terms and gives clear recommendations for photos, forms, screenshots, logos and documents.
The key difference: lossy versus lossless
JPG (JPEG) uses lossy compression. It throws away fine detail that the human eye is unlikely to notice, especially in smooth gradients and natural textures. This makes photos very small. The trade-off is that sharp edges, such as text and lines, get faint fuzzy "artefacts" around them, and every re-save loses a bit more quality.
PNG uses lossless compression. Every pixel is kept exactly. Edges stay perfectly crisp, and saving again changes nothing. The trade-off is that photos saved as PNG are often five to ten times larger than JPG.
PNG also supports transparency, so a logo can float on any background. JPG does not; transparent areas become a solid colour.
Which format for which job
| Image | Best format | Why |
|---|---|---|
| Camera photos, selfies, passport photos | JPG | Small files, natural images compress well |
| Photo and signature for exam forms | Usually JPG (follow the notice) | Most portals require JPG/JPEG |
| Screenshots of apps, websites, chats | PNG | Text stays crisp; flat colours compress well losslessly |
| Logos, icons, stickers | PNG (or SVG) | Transparency and sharp edges |
| Charts and diagrams | PNG | Lines and labels stay sharp |
| Scanned document pages | JPG for size; PNG for highest fidelity | JPG is smaller and readable; PNG keeps fine print perfect |
| Images you will keep editing | PNG | No quality loss on repeated saves |
| Website photos | WEBP or JPG | Fast loading |
Signatures: a special case
A scanned signature on white paper is mostly flat colour with sharp strokes, which suits PNG. But exam and job portals almost always demand JPG with a KB limit. In that case, save as JPG at a reasonably high quality, crop tightly around the signature, and resize to the required pixels. JPG handles a clean black-on-white signature well at small sizes. For digital signing on PDFs, a PNG with a transparent background looks the most natural. See how to sign a PDF online and our photo and signature resize guide.
Why your PNG is so big
If you save a camera photo as PNG, the file becomes huge because photos contain millions of slightly different colours, which lossless compression cannot shrink much. Convert such images to JPG with Image to JPG. For genuine PNG graphics that are still large, Compress PNG reduces the number of colours (colour quantisation), often cutting size by 50–80% with little visible change for screenshots and illustrations.
Why your JPG looks fuzzy
- Too much compression. Below about 60% quality, blocky artefacts appear. Use 75–90% for most needs.
- Saved many times. Each save as JPG loses detail. Keep an original and export from it.
- Text and line art. JPG struggles with sharp edges. Use PNG for screenshots and diagrams.
- Converted from a small source. Converting does not add detail; start from the largest version you have.
How to convert between them
- PNG, WEBP, BMP or GIF to JPG: Image to JPG.
- JPG or others to PNG: Image to PNG. This does not improve quality, but it prevents further loss when editing.
- PDF pages to images: PDF to JPG or PDF to PNG; see PDF to JPG for forms.
- WEBP from websites: read WEBP to JPG.
All these converters run in your browser, so your images are not uploaded.
What about JPEG vs JPG?
They are the same format. ".jpeg" and ".jpg" are just two file extensions, a leftover from old systems that only allowed three-letter extensions. If a portal asks for ".jpeg" specifically and rejects ".jpg", rename the extension or use Image to JPEG.
Newer formats
WEBP, AVIF and HEIC offer smaller files than JPG at similar quality and are increasingly common on websites and phones. They are excellent for storage and web pages but less widely accepted by forms and older software. When compatibility matters, JPG and PNG remain the safest choices.
Quick decision guide
- Is it a photo? Use JPG.
- Does it need transparency? Use PNG.
- Is it a screenshot, chart or logo with text? Use PNG.
- Does the form specify a format? Use exactly what the official instructions say.
- Need it smaller? Compress JPG, or reduce colours in PNG, and resize the dimensions.
What about forms and portals?
Most Indian online forms ask for JPG or JPEG photos and signatures, while some accept PNG or PDF. When in doubt, use JPG for photographs and follow the exact format named in the official notice. If you save a PNG and the form rejects it, convert with Image to JPG and compress to the stated limit. Avoid renaming a file from .png to .jpg by hand; that changes only the name, not the actual format, and some portals detect it.
Common questions
Can I get back quality by converting JPG to PNG?
No. The lost detail is gone; PNG simply stops further loss.
Which is better for printing?
Both print well at sufficient resolution. Print shops usually prefer high-quality JPG for photos and PNG or PDF for graphics with text. Size and resolution matter more than format; see how to resize in cm and DPI.
Try it now: Image to PNG is free to start and works on mobile and desktop.
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