Choosing the right image format should not require a computer science degree. Yet the sheer number of formats — JPEG, PNG, WebP, AVIF, SVG, GIF, HEIC, TIFF, BMP — is enough to make anyone hesitate. The wrong choice means larger files, lower quality, or missing features like transparency and animation. This quick reference guide cuts through the noise and tells you exactly when to use each format and why.
The Core Decision: What Are You Optimizing For?
Before diving into individual formats, understand that every format is a trade-off between three properties:
File size — how many bytes the image takes to store and transmit
Quality — how accurately the image represents the original scene
Features — transparency, animation, layers, lossless quality, metadata
No format is best at all three. JPEG is small but has no transparency. PNG has transparency but is large. WebP balances both but is not universally supported in older tools. Your job is to pick the format that optimizes for what matters most in your specific use case.
JPEG: The Workhorse for Photographs
JPEG (Joint Photographic Experts Group) is the oldest and most widely supported image format on the web. It uses lossy compression, which means it permanently removes data to achieve small file sizes. It is the default choice for photographs and complex images with many colors and gradients.
When to Use JPEG
Photographs of people, places, and products
Complex images with millions of colors and subtle gradients
Any image where small file size matters more than perfect accuracy
Email attachments and web images that need universal compatibility
When NOT to Use JPEG
Images that need transparency — JPEG does not support alpha channels
Images with sharp edges or text — JPEG compression creates visible artifacts around high-contrast boundaries
Images that will be edited and re-saved multiple times — each save degrades quality further (called "generation loss")
Line art, logos, or graphics with flat colors
JPEG Quality Settings
Quality 60–70 — small files, visible compression artifacts, suitable for thumbnails
Quality 75–85 — the sweet spot for most web images, good quality with reasonable file size
Quality 90–100 — large files, minimal compression, rarely worth the extra size for web use
PNG: The Choice for Graphics and Transparency
PNG (Portable Network Graphics) was created as a modern replacement for GIF. It uses lossless compression, meaning the image data is preserved exactly — no quality loss no matter how many times you save. PNG supports transparency, making it the go-to format for graphics that need to sit on top of any background.
When to Use PNG
Logos, icons, and UI elements with sharp edges
Graphics that require transparency
Screenshots of text-heavy interfaces
Images that will be edited and re-saved multiple times
Any image where lossless quality is essential
When NOT to Use PNG
Photographs — PNG files for photos are typically 5–10 times larger than equivalent JPEGs
Web images where file size is critical — use WebP instead for the same quality at a fraction of the size
Animations — PNG does not support animation (use APNG, WebP, or AVIF instead)
PNG Variants
PNG-8 — limited to 256 colors, smaller files, suitable for simple graphics
PNG-24 — full color, larger files, suitable for complex graphics
PNG-32 — full color with alpha transparency, largest files, suitable for graphics with semi-transparent areas
WebP: The Modern All-Rounder
WebP was created by Google as a modern replacement for both JPEG and PNG. It supports both lossy and lossless compression, transparency, and animation, all in a single format. At equivalent quality, WebP files are 25–35% smaller than JPEG and significantly smaller than PNG.
When to Use WebP
As the default format for web images — photographs, graphics, and everything in between
When you need transparency but JPEG is not an option
When you need animation but GIF is too limiting
When you want the smallest possible file size without visible quality loss
When NOT to Use WebP
When you need support in very old browsers — WebP is supported by ~97% of modern browsers but not by Internet Explorer or older Android browsers
For print production — most print workflows do not accept WebP
For email — some email clients do not render WebP images
Serving WebP with Fallbacks
For maximum compatibility, serve WebP to modern browsers and JPEG as a fallback:
Use the `` element with a WebP `` and a JPEG `` fallback
Configure your server or CDN to negotiate format based on the `Accept` header
Test in multiple browsers to ensure the fallback works
AVIF: The Next-Generation Format
AVIF (AV1 Image File Format) is the newest image format gaining wide support. It uses the AV1 video codec to achieve even better compression than WebP — typically 20% smaller than WebP at equivalent quality. It supports lossy and lossless compression, transparency, and animation.
When to Use AVIF
For hero images and other large, above-the-fold images where every kilobyte matters
When you want the smallest possible file size and can accept slightly lower browser support
For high-quality images where WebP artifacts are still visible
When NOT to Use AVIF
When you need support in all browsers — AVIF is supported by ~92% of browsers, slightly less than WebP
For print or email — support outside the browser is limited
When your toolchain does not support it — some image editors and CMS platforms do not yet handle AVIF
AVIF Quality Settings
AVIF uses a different quality scale than JPEG. AVIF quality 60 is roughly equivalent to JPEG quality 80. Start at quality 50–60 and adjust based on visual inspection.
SVG: The Vector Format
SVG (Scalable Vector Graphics) is fundamentally different from all the formats above. Instead of storing a grid of pixels, SVG stores mathematical descriptions of shapes, lines, and text. This means an SVG image is infinitely scalable — it looks crisp at any resolution, from a 16-pixel icon to a 50-foot billboard.
When to Use SVG
Logos and brand marks
Icons and UI elements
Illustrations and diagrams
Any graphic that needs to look crisp at every screen size
Graphics that need to be styled or animated with CSS or JavaScript
When NOT to Use SVG
Photographs — SVG cannot represent the complexity of a photo efficiently
Images with millions of colors and subtle gradients
Images that need to be embedded in documents that do not support SVG
SVG Advantages
Infinite resolution — no pixelation at any size
Tiny file size — simple graphics can be under 1 KB
Editable in code — SVG is XML, so you can edit it in a text editor
Stylable with CSS — change colors, strokes, and fills without re-exporting
Animatable — animate paths, transforms, and styles with CSS or JavaScript
GIF: The Animation Pioneer
GIF (Graphics Interchange Format) is one of the oldest web image formats. It supports animation and transparency but is limited to 256 colors and uses lossless compression. For most use cases, GIF has been superseded by WebP and AVIF, which offer better compression and full color support.
When to Use GIF
Short, simple animations where universal support is essential
Memes and social media content where GIF is the expected format
When you need animation in an email (WebP and AVIF animation support in email clients is limited)
When NOT to Use GIF
Anything with more than 256 colors — the color limitation produces visible banding
Long or complex animations — GIF file sizes grow rapidly with length and complexity
When file size matters — WebP animations are typically 50–70% smaller
HEIC: The Apple Native Format
HEIC (High Efficiency Image Container) is the default photo format on modern Apple devices. It uses the HEVC codec to achieve roughly twice the compression efficiency of JPEG at equivalent quality. If you take photos on an iPhone, you are already creating HEIC files.
When to Use HEIC
On Apple devices where it is the native format
For personal photo storage where file size matters and compatibility is not a concern
When your workflow is entirely within the Apple ecosystem
When NOT to Use HEIC
For web images — browser support is limited outside Safari
For sharing with non-Apple users — many systems cannot open HEIC files
For print or professional workflows — most tools do not support HEIC
Converting HEIC for Sharing
When you need to share a HEIC file outside the Apple ecosystem, convert it to JPEG or WebP:
Open the HEIC file in a conversion tool
Choose JPEG for universal compatibility or WebP for smaller file size
Set quality to 80–85% for JPEG or 78–82% for WebP
Export and share the converted file
TIFF: The Professional Print Format
TIFF (Tagged Image File Format) is the standard for print production and professional photography. It supports lossless compression, layers, multiple pages, and high bit depths. TIFF files are large, which makes them unsuitable for web use but ideal for archival and print.
When to Use TIFF
Print production where maximum quality is required
Archival storage where lossless quality is essential
Professional photo editing where layers and high bit depth are needed
When NOT to Use TIFF
Web images — TIFF files are far too large for web delivery
Email attachments — most email systems cannot handle TIFF file sizes
Mobile or consumer applications — TIFF is rarely supported outside professional tools
Quick Decision Guide
When in doubt, use this simple decision tree:
Is it a logo, icon, or illustration? → Use SVG
Is it a photograph for the web? → Use WebP (with JPEG fallback)
Is it a photograph for print? → Use TIFF
Is it a graphic that needs transparency? → Use WebP or PNG
Is it an animation? → Use WebP or AVIF (GIF if you need universal support)
Is it for an email? → Use JPEG or PNG
Is it from an iPhone? → Convert HEIC to JPEG or WebP before sharing
Conclusion
There is no single best image format — there is only the best format for your specific use case. Use SVG for vectors, WebP for most web images, JPEG as a fallback, PNG for transparency when WebP is not an option, TIFF for print, and convert HEIC before sharing outside Apple devices. Match the format to the task, and your images will look better, load faster, and work everywhere they need to.
Use WebP as your default for web photos. It produces files 25–35% smaller than JPEG at equivalent quality and is supported by ~97% of modern browsers. Serve JPEG as a fallback for older browsers using the <picture> element.
What is the difference between JPEG and PNG?
JPEG uses lossy compression and is best for photographs — small files but no transparency and quality degrades with each re-save. PNG uses lossless compression and supports transparency — perfect for graphics and logos but produces large files for photos.
Should I use AVIF or WebP?
Use AVIF when you want the smallest possible file size and can accept slightly lower browser support (~92% vs ~97% for WebP). Use WebP as your default for broader compatibility. Both are excellent for web images; AVIF is typically 20% smaller than WebP at equivalent quality.
When should I use SVG instead of PNG?
Use SVG for logos, icons, illustrations, and any graphic that needs to look crisp at every screen size. SVG is infinitely scalable, tiny in file size, and editable in code. Use PNG for raster graphics that cannot be represented as vectors, such as screenshots or digital paintings.
How do I convert HEIC files for sharing?
Open the HEIC file in a conversion tool and export as JPEG for universal compatibility or WebP for smaller file size. Set quality to 80–85% for JPEG or 78–82% for WebP. This ensures the file can be opened on any device.
