You're about to export an image and your editor asks: JPEG or PNG? It feels like a small decision, but pick wrong and you end up with a logo that has a grey halo where transparency should be, or a photo gallery that takes ten seconds to load on mobile. Most people pick based on habit — "PNG is higher quality" or "JPEG is for the web" — without knowing why either statement is only sometimes true.
The two formats aren't competing on a single "better or worse" scale. They were built to solve different problems, and once you understand what each one actually does to your image data, the right choice becomes obvious almost every time.
JPEG uses lossy compression and is best for photographs — it produces much smaller files by discarding detail the eye barely notices. PNG uses lossless compression and supports transparency, making it the right choice for logos, screenshots, UI graphics, and illustrations. Use JPEG when file size matters most; use PNG when pixel accuracy or a transparent background matters most.
What's actually different between JPEG and PNG?
Both are image file formats, but they were designed around opposite priorities — one optimizes for small files, the other for exact pixel preservation.
- JPEG (lossy compression) — analyzes the image and discards data the human eye is least likely to notice, particularly in areas of high color complexity. This is irreversible: once compressed, that detail is gone permanently. In exchange, JPEG achieves dramatically smaller files for photographic content.
- PNG (lossless compression) — re-encodes pixel data more efficiently without discarding anything. A PNG always decodes to a pixel-perfect copy of the source image. It also supports an alpha channel, meaning parts of the image can be fully or partially transparent.
The practical consequence: JPEG shrinks photographs far better than PNG can, because photographs are full of the kind of subtle, high-frequency detail JPEG is designed to discard. PNG shines on flat-color content — logos, UI screenshots, line art — where there's little detail to discard in the first place, and where lossless accuracy actually matters (no soft edges, no transparency artifacts).
Why the right choice matters
Picking the wrong format isn't just a minor inefficiency — it shows up as visible problems or real costs:
- Page speed. A photo gallery saved as PNG can be 5–10x larger than the same images as JPEG, directly hurting Largest Contentful Paint and mobile load times.
- Broken transparency. Saving a logo with a transparent background as JPEG bakes in a solid white (or black) box where transparency used to be — there's no way to undo this after export.
- Visible artifacts. Saving a screenshot or UI mockup as JPEG introduces blurring and color banding around sharp edges and text — exactly the kind of content JPEG handles worst.
- Storage and bandwidth costs. At scale — a CMS, an app, a CDN — using the wrong format across thousands of images multiplies storage and transfer costs for no visual benefit.
Step-by-step: how to choose the right format
- Ask if the image needs transparency. If any part of the image needs to show what's behind it — a logo over a colored header, an icon on a varying background — JPEG is disqualified immediately. It has no alpha channel under any settings. Use PNG (or WebP).
- Look at the content type. Photographs, gradients, and complex textures (real-world scenes, product photography, nature shots) compress extremely well as JPEG with minimal visible loss. Flat-color graphics, text, line art, and screenshots compress poorly as JPEG and beautifully as PNG.
- For photographs, pick a JPEG quality setting. Most editors offer 0–100 (or 1–12). For web use, 75–85 is the practical sweet spot — visually near-identical to 100 but at a fraction of the file size. Go below 60 only when file size is critical and some softness is acceptable.
- For graphics, export as PNG and then optimize it. A raw PNG export from Figma or Photoshop carries unnecessary metadata. Run it through a lossless optimizer (PNGQuant + OptiPNG, or a browser tool) to cut 40–70% of the file size with zero visible change.
- Compare the result at real size. Don't judge quality zoomed in at 400% — view the image at the size it will actually display. JPEG artifacts that are obvious at high zoom often vanish entirely at normal viewing size.
- Consider WebP as a third option. WebP supports both lossy and lossless modes plus transparency, generally beating both JPEG and PNG on file size at equivalent quality. If your platform supports it, it's worth using instead of either — though PNG and JPEG remain the safer universal fallback.
- When in doubt, test both and measure. Export the same image as JPEG (quality 85) and optimized PNG, then compare file size and visual quality side by side. For ambiguous cases — a screenshot with a gradient background, for example — the numbers will settle the question.
Common mistakes that cost you quality or speed
1. Using PNG for every image "to be safe"
PNG feels like the "higher quality" default, so it's tempting to use it everywhere. But for photographs, this is actively counterproductive — you get a file 3–8x larger than a well-compressed JPEG with no visible quality benefit, since JPEG at quality 85+ is already near-indistinguishable from lossless for photographic content.
2. Saving a transparent PNG as JPEG to "shrink it"
This is one of the most common irreversible mistakes. JPEG has no transparency support, so any transparent area gets flattened to a solid color (usually white). If you need a smaller file and transparency, optimize the PNG instead, or convert to WebP — never JPEG.
3. Re-saving a JPEG repeatedly during editing
Every time a JPEG is opened, edited, and re-saved as JPEG, another round of lossy compression is applied on top of the last one, compounding artifacts. Keep a lossless master copy (PNG, TIFF, or your editor's native format) and only export to JPEG as the final step.
4. Ignoring the actual display size
Exporting a screenshot at 4x its display resolution and choosing PNG "for quality" produces an unnecessarily massive file. Match the export resolution to where the image will actually be shown, then pick the format based on content type — not the other way around.
Real-world examples
These are representative results from exporting the same source image as both JPEG (quality 85) and optimized PNG:
The pattern holds consistently: photographic and gradient-heavy content favors JPEG by a wide margin, while flat-color, text-heavy, or transparency-dependent content has no real substitute for PNG.
JPEG vs PNG comparison table
A side-by-side look at how the two formats actually differ on the properties that matter most for everyday decisions.
| Property | JPEG | PNG |
|---|---|---|
| Compression type | Lossy | Lossless |
| Transparency support | No | Yes (alpha channel) |
| Best for photographs | Excellent | Poor — large files |
| Best for flat graphics / text | Poor — artifacts | Excellent |
| Typical file size | Small | Larger (unless content is flat-color) |
| Quality after repeated re-saving | Degrades each time | No degradation |
| Typical use cases | Photos, banners, product shots, blog hero images | Logos, icons, screenshots, illustrations, UI assets |
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