Key Takeaways
- JPG suits photographs; PNG suits graphics with sharp edges or transparency; WebP can replace both in most modern browsers.
- HEIC is the default iPhone format — convert to JPG before sharing outside Apple devices or uploading to most web services.
- Conversion order matters: always convert from the highest-quality original you have rather than converting back and forth between lossy formats.
When Format Choice Affects the Result
Image format determines file size, quality, transparency support, and compatibility. JPG compresses photographs efficiently but discards data at each save, which causes artifacts on text, logos, and sharp edges. PNG is lossless and supports transparency, making it better for screenshots, UI elements, and graphics. WebP combines good compression with transparency support and works in most modern browsers. AVIF offers better compression than WebP but has narrower tool and platform support.
JPG: Best Use Cases
Use JPG for photographs, product images, and realistic scenes where a small quality reduction is acceptable. Avoid JPG for images with text overlays, line art, logos, or transparent backgrounds. The compression is lossy, so repeated saves of the same JPG file reduce quality each time. Keep a PNG or original format for any image you expect to re-edit or reuse as a source.
PNG: Best Use Cases
Use PNG for screenshots, logos, icons, UI elements, and any image where you need a transparent background. PNG is lossless, so text and sharp edges remain crisp. PNG files are larger than JPG for photographs, so use it selectively. If transparency is not needed, converting a large PNG photograph to WebP or JPG reduces file size without visible quality loss.
WebP: When to Switch
WebP suits web pages where browser compatibility is acceptable and you want smaller files than JPG or PNG. Most modern browsers support WebP, but email clients, document upload forms, government portals, and print workflows may expect JPG or PNG. Check the destination requirements before converting — a format that is smaller is only better if it is also accepted.
HEIC and AVIF Compatibility
HEIC is the default photo format on iPhones and iPads but is not widely supported outside Apple software. Most web services, forms, and printers expect JPG or PNG. Convert HEIC to JPG before uploading to any service not designed for Apple files. AVIF offers excellent compression but platform and tool support is still expanding — verify compatibility before deploying AVIF images in production.
SVG for Scalable Graphics
SVG is a vector format for logos, icons, and illustrations that need to scale without quality loss. It is not suitable for photographs. Converting a raster image like a JPG to SVG does not create a true vector — use SVG for graphics originally created in vector software. Converting SVG to PNG is useful when a site, app, or document requires a fixed-resolution raster image.
Conversion Order and Quality Loss
Start from the highest-quality original you have. Converting JPG to PNG does not recover lost compression data — the PNG will be larger but not higher quality. Converting PNG to WebP is generally safe and often reduces size without visible loss. Never compress and re-save a JPG multiple times; use the original as the source for every format you need to produce.