Most image problems are format problems wearing a disguise. A logo looks fuzzy because it was saved as JPG. A product photo weighs 8 MB because it is an uncompressed PNG. A transparent sticker gets a black background because someone converted it to JPG. The fix is usually not —better quality— — it is the right container for the job.
The short answer
| Format | Best for | Transparency | Animation | Compression | Watch out for |
|---|---|---|---|---|---|
| JPG / JPEG | Photographs, email attachments, web photos | No | No | Lossy | Artifacts around text and sharp edges; no transparency |
| PNG | Screenshots, logos, UI, images with transparency | Yes | No | Lossless | Large for photos; can be much bigger than JPG |
| WebP | Web images, thumbnails, modern browsers | Yes | Yes | Lossy or lossless | Older software may not open it; some platforms re-encode it |
| GIF | Simple animations, tiny graphics | Yes (1-bit) | Yes | Lossless (palette) | 256 colours; ugly banding in photos; huge animations |
| TIFF | Print masters, scanning, archiving | Yes | Yes (multi-page) | Usually lossless | Very large; not great for the web |
| SVG | Logos, icons, diagrams, anything that must scale | Yes | Yes (SMIL/CSS) | Vector | Not for photographs; can contain scripts when opened in a browser |
| BMP | Legacy Windows workflows | Limited | No | Uncompressed | Enormous files; rarely the right choice today |
| HEIC / HEIF | Photos from newer iPhones and some Android phones | Yes | Yes | Lossy or lossless | Compatibility; many websites and Windows apps still struggle |
Photographs: JPG, or WebP when you can
JPG is designed for photographs: smooth gradients, millions of colours, and a compression method that throws away detail the eye is less likely to notice. A well-encoded JPG at 80—85% quality is usually visually indistinguishable from the original at normal viewing size, and a fraction of the weight.
WebP can do the same job with roughly 25—35% smaller files at comparable quality, and it supports transparency. It is well supported in current browsers. The catch is the rest of the pipeline: an old desktop publisher, a print shop, a government portal, or a social platform may not accept WebP or may re-encode it badly. For a website you control, WebP is a good default. For a file you are sending to someone else, JPG is the safer common denominator.
Do not convert a JPG to PNG expecting better quality. The lost detail is already gone; PNG will only make the file bigger.
Screenshots, logos and transparency: PNG
PNG is lossless, which makes it the right choice for screenshots, diagrams, text, logos and anything with a transparent background. A PNG preserves sharp edges and exact colours. The cost is size: a photographic PNG can be several times larger than a good JPG.
For a logo or icon that needs to scale cleanly, SVG is better than PNG if you have the vector source. For a screenshot that will be pasted into a document, PNG is usually ideal. For a transparent product cut-out on a website, WebP or PNG both work; WebP is smaller.
When converting a transparent PNG to JPG, the transparency has to become something. Many tools fill it with white, some with black. If the result looks wrong, flatten it against the colour it will actually sit on before converting.
The web: WebP first, JPG/PNG as fallback
For a website, the practical rule is: serve WebP or AVIF where supported, and keep a JPG or PNG fallback for the rest. Modern browsers support WebP broadly. The bigger variable is the platform — a CMS, marketplace or email client may re-encode the image or refuse the format.
Whatever the format, the dimensions matter more than the quality slider. A 4,000-pixel-wide hero image displayed at 1,200 pixels is wasting bandwidth no matter how carefully it was compressed. Resize first, then compress. The image resizer and image compressor do both locally.
Print: TIFF, PDF, or a high-quality JPG
For print, the priorities flip: resolution, colour profile and lack of compression artifacts matter more than file size. A print shop may ask for TIFF, a high-quality JPG, or a PDF with images embedded at 300 DPI. TIFF is a good archival master because it is typically lossless and supports layers and multiple pages, but it is not a web format.
If you are sending a photo to a printer, do not aggressively compress it first. Compress a separate web copy. Keep the master at the highest quality you have.
Logos and icons: SVG
SVG is not a picture of shapes; it is a set of instructions for drawing them. That means it stays sharp at any size, and a simple logo can be a few kilobytes. It is the right format for logos, icons, charts and diagrams when you have the source.
SVG is the wrong format for photographs. It is also worth treating an SVG from an untrusted source carefully: SVG can contain scripts and external references. For a logo you created or received from a trusted designer, that is not a practical concern. For a random download, open it in a viewer rather than a browser with access to sensitive sessions.
If you only have a PNG logo, converting it to SVG does not recreate the vector data. It may wrap the bitmap in an SVG container, which looks like an SVG but does not scale cleanly. Use SVG to PNG when you need a raster copy, not the other way around.
GIF and animation
GIF is still useful for very short, simple animations and for compatibility in chat apps. It is a poor choice for photographic animation: the 256-colour palette produces banding, and the file can be enormous. For modern web animation, a short MP4 or WebM is usually smaller and better looking; for simple UI motion, CSS or SVG is better still.
If a platform insists on GIF, keep the dimensions small and the frame count low. A 10-second screen recording at full resolution will be a multi-megabyte GIF no matter how good the compressor is.
HEIC, BMP and the awkward formats
HEIC is the default capture format on many iPhones. It is efficient and supports transparency and animation, but compatibility is uneven. If a website, a Windows app or a print service refuses it, convert to JPG with HEIC to JPG. Keep the original if you might want the extra quality later.
BMP is a legacy Windows bitmap: simple, uncompressed and large. There are still industrial and legacy workflows that expect it, but for anything modern, PNG or TIFF is a better lossless container.
TIFF is worth keeping for scans and print masters. If a portal refuses TIFF, convert a copy to PNG or JPG rather than deleting the master. TIFF to PNG is a reasonable compatibility move.
Conversion mistakes to avoid
- PNG to JPG with transparency. The transparent area becomes a solid colour. Flatten it deliberately first.
- JPG to PNG for —quality—. It cannot restore detail that JPG already discarded; it only increases the file size.
- Repeated re-saving. Every lossy save loses a little more. Edit from the master, not from the last compressed copy.
- Upscaling. Making a 600-pixel image 2,400 pixels does not add real detail. Start with the largest source you have.
- Ignoring orientation metadata. A photo can look upright in one viewer and sideways in another. Check after conversion, especially after EXIF removal.
- CMYK vs RGB. A JPG exported in CMYK may look wrong on the web. Use RGB for screens, CMYK for professional print.
- Converting the only copy. Keep the original; converters can change colour profiles and metadata even when the pixels look the same.
A simple decision tree
- Is it a photograph? Use JPG. Use WebP for a website you control.
- Is it a screenshot, logo, icon or transparent graphic? Use PNG, or SVG if you have the vector source.
- Is it going to a printer or an archive? Use TIFF or a high-quality PDF, and keep the master.
- Is it a short animation? Use MP4/WebM for video-like motion; GIF only when a platform forces it.
- Is it from an iPhone and the recipient cannot open it? Convert HEIC to JPG and keep the original.
- Is the file too large? Resize first, then choose the format, then compress.
That is most of the decision. The remaining 10% is the recipient—s requirements, which are worth checking before you convert anything important.