JPEG vs PNG: which image format should you choose?
JPEG and PNG solve different problems. JPEG uses lossy compression that is efficient for photographs, while PNG uses lossless compression and an alpha channel that suit graphics, screenshots, and transparency. The right choice depends on your image, not on a universal winner.
Neither format wins every time. Match the format to the image: JPEG for photographs where a small file matters, PNG for graphics, transparency, text, and any master you will edit again. Use the scenario table below to decide case by case.
Lossy versus lossless: the core difference
JPEG is a lossy format. Its encoder splits the picture into blocks, transforms each block into frequency components with a discrete cosine transform, and quantizes those components, permanently discarding fine detail your eye is less likely to notice. Decoding a JPEG therefore never reproduces the original pixels exactly.
PNG is a lossless format. It compresses with a filtering step followed by DEFLATE, and decompression restores the original samples bit for bit. Nothing is thrown away, so a PNG re-saved many times stays identical to the first save.
That single distinction drives most of the trade-offs below: JPEG buys small files by giving up exactness, while PNG guarantees exactness at the cost of larger files on photographic content.
Transparency and alpha
PNG supports full alpha transparency: each pixel can carry its own opacity, so a logo can sit cleanly on any background with smooth anti-aliased edges. This is defined as part of the PNG specification's colour types.
JPEG has no alpha channel at all. Any image that must have a transparent background — an app icon, a watermark, a UI element — cannot be a JPEG, so PNG (or WebP) is required for those cases.
Photo artifacts and where each format shines
On photographs, JPEG's rounding is hidden by smooth gradients and texture, so high-quality JPEGs look nearly identical to the source while staying small. This is exactly the content the format was designed for.
On hard edges, flat colour, and text, the same rounding becomes visible as blocking around edges and halos near high-contrast lines. PNG avoids these artifacts entirely because it stores the exact samples, which is why screenshots and diagrams look crisp as PNG and muddy as low-quality JPEG.
Repeated editing and generational loss
Because JPEG re-applies lossy compression on every save, editing and re-exporting the same JPEG repeatedly compounds the loss — a phenomenon often called generational loss. Colours drift and artifacts accumulate with each round trip.
PNG has no generational loss: re-saving reproduces the same pixels every time. If a file is a working master you will open, tweak, and export again, PNG protects it. Keep an untouched master and export a fresh JPEG only when you need the final small file.
Screenshots and text sharpness
Screenshots are mostly sharp UI edges, solid fills, and small text — precisely the content JPEG handles worst. A JPEG screenshot shows fuzzy text and ringing around window chrome even at high quality.
PNG keeps every edge and character pixel-exact, so screenshots, code snippets, and documentation images stay legible. For any capture that includes readable text, PNG is the safer default.
Attribute comparison
| Attribute | JPEG | PNG |
|---|---|---|
| Compression | Lossy | Lossless |
| Transparency | None | Full alpha channel |
| Best content | Photographs, continuous tone | Graphics, text, screenshots |
| Repeated re-saves | Compounds loss | No quality change |
| Typical file size on photos | Smaller | Larger |
| Universal decoder support | Yes | Yes |
Print handoff
For print, exactness and predictable colour matter more than file size, so a lossless master avoids compression artifacts surviving into the final piece. PNG or another lossless format is a safe handoff for logos and line art headed to a printer.
Photographs destined for print are commonly delivered as high-quality JPEGs or as lossless masters, depending on the printer's workflow. Confirm the format and colour requirements with the print provider rather than assuming, and always keep a lossless original in reserve.
Worked example: choosing between JPEG and PNG
- Ask whether the image is a photograph
If it is a photo or realistic render and file size matters, JPEG is usually the efficient choice. If it is a graphic, screenshot, or logo, favour PNG.
- Check for transparency or text
If the image needs a transparent background or contains readable text and sharp edges, choose PNG — JPEG cannot do transparency and blurs text.
- Consider whether you will edit it again
If this is a working master you will re-open and re-export, keep it as PNG to avoid generational loss, then export a JPEG only for the final small deliverable.
Scenario decision table
| Scenario | Recommended | Why |
|---|---|---|
| Photos | JPEG | Lossy compression is efficient on continuous tone and hides its rounding in gradients |
| Logos | PNG | Lossless with alpha keeps sharp edges and transparent backgrounds intact |
| Screenshots | PNG | Exact pixels keep UI edges and small text legible |
| Web delivery | Either | JPEG for photos, PNG for graphics; pick per image and consider WebP as a modern option |
| Printing | PNG or lossless master | Avoids compression artifacts; confirm the print provider's required format |
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Frequently asked questions
- Is JPEG or PNG better?
- Neither is universally better. JPEG is better for photographs where small files matter; PNG is better for graphics, text, transparency, and masters you will edit again.
- Which format supports transparency?
- PNG supports a full alpha channel for transparent backgrounds. JPEG has no transparency, so use PNG (or WebP) when you need it.
- Does converting a photo from JPEG to PNG restore lost quality?
- No. JPEG discards detail permanently. Converting to PNG afterwards only preserves the already-degraded pixels losslessly; it cannot recover what JPEG removed.
- Why do my screenshots look blurry as JPEG?
- Screenshots contain sharp edges and small text, which reveal JPEG's lossy rounding as fuzz and ringing. Save screenshots as PNG to keep them crisp.
- Which is smaller, JPEG or PNG?
- On photographs JPEG files are usually much smaller because lossy compression discards detail. On flat graphics with few colours, PNG can be competitive or smaller.
- Should I keep a PNG master and export JPEG at the end?
- Yes, that is a good workflow. Editing a lossless PNG master avoids generational loss, and you export a small JPEG only for the final delivery when appropriate.