JPG vs PNG vs WebP — Which Image Format Should You Use?

Choosing the wrong image format costs you file size, quality, or compatibility. Here is a plain-English breakdown of the three formats you will encounter most often — and exactly when to use each one.

The Three Formats at a Glance

Full Comparison

When to Use Each Format

Use JPG when…

• You are sharing or printing photographs
• You need universal compatibility (email, WhatsApp, older software)
• File size matters and you do not need transparency
• The image has smooth gradients, skin tones, or natural scenes

Use PNG when…

• Your image has a transparent background (logos, stickers, cutouts)
• The image contains text, sharp lines, or flat colours (screenshots, UI mockups)
• You are doing multiple rounds of editing and cannot afford quality loss
• You need a pixel-perfect copy of a graphic

Use WebP when…

• You are publishing images on a website and want faster load times
• You need transparency but want smaller files than PNG
• Your audience uses modern browsers (Chrome, Firefox, Safari 14+, Edge)

The File Size Reality

To put the size difference in concrete terms: a typical 12-megapixel phone photo might be:

• JPG at 85% quality: ~2.5 MB
• PNG: ~9 MB
• WebP at equivalent quality: ~1.7 MB

For a website with 20 product images, switching from JPG to WebP saves roughly 16 MB of data per page load — meaningfully faster on mobile connections.

What About AVIF, HEIC, and Others?

AVIF is the next-generation format after WebP — 50% smaller than JPG at similar quality. Browser support is growing fast. Use it for cutting-edge web performance.

HEIC is Apple's format for iPhone photos. It has excellent compression but poor compatibility outside Apple devices. Convert to JPG before sharing widely.

GIF is outdated for animation — use WebP animated or MP4 instead. File sizes are dramatically smaller.

How JPG compression actually works

JPG divides your image into 8×8 pixel blocks. Each block gets transformed using a mathematical process called the Discrete Cosine Transform, which separates broad colour information from fine detail. The fine detail — things your eye is less sensitive to — gets discarded or heavily rounded to achieve smaller file sizes.

This is why JPG struggles with images containing hard edges or flat colour areas. When two very different colours sit next to each other (like black text on a white background), the 8×8 block boundaries become visible as smudged, coloured noise. You have probably seen this as blurry fringes around text in a heavily compressed screenshot. PNG avoids this entirely because it stores pixel data without any lossy step.

A practical takeaway: JPG quality loss is not uniform. It affects sharp contrasts much more than smooth gradients. A photograph of a mountain at sunset compresses beautifully. A screenshot of your inbox does not.

What quality setting should you use for JPG?

Most export tools offer a quality slider from 1 to 100. Here is where the trade-offs land in practice:

• Quality 85–90: The sweet spot for web images. Files are 50–70% smaller than quality 100 with virtually no visible difference on screen.
• Quality 70–80: Good for thumbnails and preview images. Compression artefacts may appear at 1:1 zoom but disappear at normal viewing distances.
• Quality 60 and below: Visible degradation. The "blocky" look becomes hard to ignore. Only appropriate for tiny preview tiles or situations where bandwidth is severely constrained.
• Quality 100: Still lossy — the JPG format cannot achieve true lossless output, even at maximum quality. If you need to preserve originals without any degradation at all, use PNG or TIFF as your archiving format.

The same principle applies to WebP. Quality 80–85 is the sweet spot for web publishing, producing files roughly 25–35% smaller than JPG at quality 85 with comparable visual output at normal viewing sizes.

PNG for screenshots — why it matters more than you think

Screenshots are a case where PNG wins decisively, and the reason is straightforward. A screenshot contains hard pixel edges, flat background colours, and rendered text. JPG's block-based compression blurs those edges and creates coloured noise around every letter — even at quality 90.

Try it yourself: take a screenshot of any website and save it as JPG at 80% quality. Zoom in on the body text. You will see faint coloured fringes around each character, like a slightly out-of-focus printout. Save the same screenshot as PNG and zoom in — the text is perfectly sharp at every zoom level because no pixels were modified. For anything containing text, UI elements, diagrams, or flat graphic design, PNG is the right format without exception.

The file size difference feels painful at first — a PNG screenshot of a typical webpage might be 400 KB where the JPG was 80 KB. But the quality difference is not a matter of preference; it is the difference between a legible document and a subtly degraded one.

Frequently Asked Questions

Should I use JPG or PNG for photos?

JPG. It compresses photographs to a fraction of the PNG size with barely visible quality loss. Only use PNG for photos if you need pixel-perfect accuracy or transparency.

Is WebP supported everywhere?

All browsers released after 2020 support WebP, including Chrome, Firefox, Safari 14+, and Edge. However, some desktop apps (older Photoshop, Windows Photo Viewer before Win10) cannot open WebP. If compatibility is critical, stick to JPG or PNG.

Does converting JPG to PNG improve quality?

No. Converting a lossy format (JPG) to lossless (PNG) does not recover lost detail — it just stores the same pixels in a larger file. Always work from the original highest-quality source.

Which format is best for SEO?

WebP gives the best page speed scores, which Google uses as a ranking signal. Use WebP for all web images with a JPG fallback for older browsers. Always add descriptive alt text regardless of format.

What is the difference between lossy and lossless compression?

Lossy compression permanently removes some image data to reduce file size. Once you save in a lossy format, the discarded information is gone — you cannot get it back later. Lossless compression reorganises the data more efficiently but keeps every pixel intact. JPG is lossy. PNG is lossless. WebP supports both modes; the lossless WebP mode produces files about 25% smaller than equivalent PNGs.

Why do so many websites still use JPG instead of WebP?

Legacy infrastructure. Many content management systems, CDNs, and image pipelines were configured years ago when JPG was the universal safe choice. Migrating means re-encoding an entire image library and updating delivery logic — not a trivial project for a large site. The benefits are real (25–35% smaller files), but the migration cost leads most teams to keep existing JPGs and only output WebP for new content.

Can you convert PNG to JPG without losing quality?

Not entirely. Converting from lossless (PNG) to lossy (JPG) always discards some data. At quality 90+ the difference is barely visible for photographs, but for screenshots and diagrams the compression noise around sharp edges and text becomes noticeable. A better option for reducing PNG file sizes without lossy trade-offs is converting PNG to WebP in lossless mode — you get smaller files with zero quality loss.

Can I batch convert a folder of images at once?

Yes. Convertlo supports batch conversion — drop multiple files at once and download the results as a single zip file. This is useful when you have a full product image library to convert from PNG to WebP, or a folder of phone photos you want to standardise as JPGs before uploading.