Guide

The Complete Image Format Guide

JPG, PNG, GIF, WebP, AVIF, HEIC, TIFF, BMP, SVG — each format has different strengths, weaknesses, and ideal use cases. This comprehensive reference explains every major format in detail and helps you choose the right one for any situation.

Image Prep Kit Editorial Team

14 min read

Fundamentals

Understanding image formats

Image formats differ in how they store pixel data, whether they use compression, and what features they support.

Raster vs vector formats

Image formats fall into two broad categories: raster and vector. Raster formats (JPG, PNG, GIF, WebP, AVIF, HEIC, TIFF, BMP) store images as a grid of pixels, where each pixel has a specific color value. Raster images have a fixed resolution and lose quality when scaled up. Vector formats (SVG, EPS, PDF with vector content) store images as mathematical descriptions of shapes, lines, and curves, which can be scaled to any size without quality loss. Photographs are always raster; logos, icons, and illustrations are often vector. Understanding this distinction is the first step in choosing the right format for your content.

Lossy vs lossless compression

Compression reduces file size by eliminating redundant data. Lossy compression (JPG, WebP lossy, AVIF lossy, HEIC) permanently discards some image data, achieving smaller files at the cost of some quality that is usually invisible to the human eye at moderate settings. Lossless compression (PNG, GIF, WebP lossless, AVIF lossless, TIFF with compression) preserves every pixel exactly, achieving more modest size reductions. Lossy is ideal for photographs where minor quality loss is acceptable; lossless is required for text, screenshots, line art, and images that will be edited repeatedly. Some formats like WebP and AVIF support both modes, giving you flexibility.

Color depth and channels

Color depth determines how many colors an image can represent. 8-bit color supports 16.7 million colors (24-bit RGB), which is sufficient for most web and print use. 10-bit and 12-bit color support over a billion colors, enabling HDR and smoother gradients. Channels refer to the color components: RGB has red, green, and blue channels; RGBA adds an alpha (transparency) channel; CMYK is used for print. Formats vary in supported color depth and channels: JPG supports 8-bit RGB or CMYK without alpha; PNG supports 8-bit or 16-bit RGB with alpha; AVIF supports 8, 10, and 12-bit with alpha; HEIC supports 8, 10, and 12-bit.

Format

JPG / JPEG

The most widely used image format in the world, optimized for photographic content.

Overview and history

JPG (Joint Photographic Experts Group) was standardized in 1992 and remains the most common image format on the web and in digital photography. It uses lossy compression based on discrete cosine transform (DCT), which is highly effective for photographic content but produces visible artifacts around sharp edges and text. JPG supports 8-bit RGB or CMYK color, does not support transparency, and does not support animation. The format is universally supported by every browser, device, and image editing application, making it the safest choice for maximum compatibility. JPG files typically use the .jpg or .jpeg extension.

Strengths and weaknesses

JPG's greatest strength is universal compatibility and efficient compression for photographs. At quality 80 to 85, JPG produces small files with excellent visual quality for photos. The format is well-understood, fast to encode and decode, and supported by every piece of image software ever made. Its weaknesses include no transparency support, visible artifacts on text and line art, no animation, and 8-bit color only. Repeatedly editing and re-saving a JPG file causes cumulative quality degradation (generation loss), so always keep an uncompressed master for editing and export to JPG only as the final step. JPG is not suitable for screenshots, logos, or images with sharp text.

Best use cases

Use JPG for photographs, hero images, blog post photos, product photography, and any image where the content is photographic and transparency is not needed. JPG is the ideal format for email attachments, social media uploads, and any scenario where maximum compatibility is required. For web use, export JPG at quality 80 to 85 and resize to the displayed dimensions. Avoid using JPG for logos, icons, screenshots, text graphics, transparent images, or images that will be edited multiple times. For those use cases, use PNG, WebP, or SVG instead. When in doubt for a photograph, JPG is always a safe choice.

Format

PNG

The lossless format of choice for graphics, screenshots, and transparent images.

Overview and history

PNG (Portable Network Graphics) was created in 1996 as a patent-free alternative to GIF, and it has become the standard lossless format for web graphics. PNG uses DEFLATE compression, which is lossless and works well for images with large areas of solid color, such as screenshots, logos, and text. PNG supports 8-bit and 16-bit color, full alpha transparency (256 levels of partial transparency), and interlacing for progressive display. It does not support animation (that was MNG, a separate format that never gained traction) or lossy compression. PNG files are universally supported by all modern browsers and image editors.

Strengths and weaknesses

PNG's strengths include perfect lossless quality, full alpha transparency support, and excellent compression for graphics with flat colors and sharp edges. It is the best format for screenshots, logos, icons, diagrams, and any image where every pixel must be preserved exactly. PNG's primary weakness is file size for photographic content: a PNG photograph can be 3 to 10 times larger than an equivalent JPG because lossless compression cannot discard the subtle noise and texture variations in photos. PNG also does not support animation or CMYK color, making it unsuitable for print workflows. For web use, large PNG files slow down page loads and hurt Core Web Vitals scores.

Best use cases

Use PNG for screenshots, logos, icons, diagrams, charts, illustrations, text graphics, and any image requiring transparency or lossless quality. PNG is essential for images with transparent backgrounds that need to overlay different colored backgrounds. For web delivery, consider converting PNG graphics to WebP or AVIF lossless for 20 to 40 percent smaller files with identical quality. Avoid using PNG for photographs, as the file size will be unnecessarily large. If you need a transparent photograph, use WebP or AVIF with alpha, which produce much smaller files than PNG for photographic content with transparency.

Format

GIF

The classic animated image format, still popular despite its limitations.

Overview and history

GIF (Graphics Interchange Format) was introduced in 1987 and is one of the oldest image formats still in widespread use. GIF uses lossless LZW compression but is limited to 256 colors per frame (8-bit palette), which makes it unsuitable for photographs. GIF supports animation (multiple frames with timing), 1-bit transparency (a pixel is either fully transparent or fully opaque, no partial transparency), and interlacing. Despite its age and technical limitations, GIF remains immensely popular for short animations, memes, and reaction images on social media and messaging platforms. The format is universally supported.

Strengths and weaknesses

GIF's main strength is universal animation support and simplicity. Every browser and messaging app supports animated GIFs, and the format is well-understood. Its weaknesses are severe: 256-color limit causes banding and dithering in photographs and gradients; 1-bit transparency produces jagged edges; file sizes are large compared to modern video formats; no audio support; and no modern compression. A 5-second animated GIF can easily be 5 to 10 megabytes, while an equivalent MP4 video might be 500 kilobytes. For this reason, many platforms that accept GIFs actually convert them to MP4 or WebM behind the scenes for delivery.

Best use cases

Use GIF for short, simple animations with limited colors, such as icons, loading spinners, and simple memes. For photographic animations or longer clips, use MP4 or WebM video instead, which offer dramatically smaller file sizes and better quality. Many platforms support looping muted MP4 videos as a GIF replacement, and this is the recommended approach for web performance. If you must use GIF, keep the dimensions small (under 500 pixels wide), limit the frame count, and use a limited color palette to minimize file size. Avoid using GIF for static images, as PNG or WebP will produce smaller files with better quality.

Format

WebP

Google's modern format that combines the best of JPG and PNG with animation support.

Overview and history

WebP was developed by Google and first released in 2010, based on the VP8 video codec's intra-frame compression. It supports both lossy and lossless compression, alpha transparency, animation, and metadata. WebP lossy typically produces files 25 to 35 percent smaller than JPG at equivalent quality, while WebP lossless produces files 25 to 35 percent smaller than PNG. After years of limited browser support, WebP is now supported by all major browsers (Chrome, Firefox, Safari 14+, Edge) and covers over 97 percent of global web users. WordPress has supported WebP upload and automatic generation since version 5.8.

Strengths and weaknesses

WebP's greatest strength is versatility: it can replace both JPG (for photographs) and PNG (for graphics and transparency) with a single format that produces smaller files in both modes. WebP encoding and decoding are fast, the tooling ecosystem is mature, and browser support is near-universal. Animated WebP can replace animated GIF with much smaller files and better quality. WebP's weaknesses include 8-bit color only (no HDR or 10-bit), slightly less compression efficiency than AVIF for photographic content, and limited support in some older image editing software (though Photoshop, GIMP, and ImageMagick all support it now).

Best use cases

Use WebP as the primary modern format for web delivery when you want smaller files than JPG or PNG with broad browser support. WebP is excellent for photographs, graphics, screenshots, transparent images, and short animations. For maximum compatibility, serve WebP with a JPG or PNG fallback using the picture element or content negotiation. WebP is the default modern format for WordPress, most CDNs, and many image optimization plugins. If you are migrating from JPG and PNG to a single modern format and want the safest choice, WebP is the most well-supported option available today.

Format

AVIF

The newest and most efficient widely supported format, based on the AV1 video codec.

Overview and history

AVIF (AV1 Image File Format) is based on the AV1 video codec developed by the Alliance for Open Media, a consortium including Google, Mozilla, Netflix, Amazon, and others. It was standardized in 2019 and began seeing browser support in 2020. AVIF supports both lossy and lossless compression, alpha transparency, 8-bit, 10-bit, and 12-bit color depth, HDR (PQ and HLG transfer functions), wide color gamut (BT.2020), film grain synthesis, and animation. AVIF typically produces files 20 to 50 percent smaller than WebP at equivalent visual quality, making it the most efficient widely available image format. Browser support includes Chrome 85+, Firefox 93+, and Safari 16+.

Strengths and weaknesses

AVIF's greatest strength is compression efficiency: it consistently outperforms WebP, JPG, and PNG across photographic content, especially at low bitrates where it produces more graceful degradation with less blocking and banding. Support for HDR, 10-bit and 12-bit color, and wide color gamut makes AVIF future-proof for high-end displays. AVIF's weaknesses include slower encoding times (3 to 10 times slower than WebP), slightly higher CPU usage for decoding on older devices, and narrower browser support than WebP (approximately 92 to 95 percent global coverage). Image editing support is growing but less mature than WebP, with Photoshop 2022+ and GIMP (via plugins) supporting it.

Best use cases

Use AVIF when maximum compression efficiency is the top priority, especially for photographic content, hero images, product photography, and any image where every kilobyte reduction improves load times. AVIF is ideal for high-traffic websites, e-commerce product pages, and image-heavy portfolios. For HDR content or 10-bit photography, AVIF is currently the only widely supported web format. Serve AVIF with WebP and JPG fallbacks using the picture element or CDN content negotiation. For sites using a CDN with automatic format conversion, enabling AVIF alongside WebP delivers the best of both formats with minimal effort. AVIF is the recommended primary format for forward-looking web optimization in 2026.

Format

HEIC / HEIF

Apple's default photo format, offering excellent compression for mobile photography.

Overview and history

HEIC (High Efficiency Image Container) is the container format for HEIF (High Efficiency Image File Format) images encoded with the HEVC (H.265) video codec. Apple adopted HEIC as the default photo format on iOS 11 and macOS High Sierra in 2017, and it remains the default on iPhones and iPads. HEIC supports lossy and lossless compression, alpha transparency, 8-bit, 10-bit, and 12-bit color, HDR, animation, image sequences, and embedded depth maps. HEIC files are typically 40 to 50 percent smaller than equivalent JPG files with the same visual quality, which is why Apple adopted it to save storage space on mobile devices.

Strengths and weaknesses

HEIC's strengths include excellent compression efficiency (comparable to AVIF for photographic content), support for advanced features like depth maps and image sequences, and native support on all Apple devices. The format is ideal for mobile photography where storage space is limited. HEIC's primary weakness is limited compatibility outside the Apple ecosystem: Windows requires a paid HEVC extension or third-party software, many image editors do not support it natively, and no major web browser supports HEIC rendering due to patent licensing concerns with HEVC. This makes HEIC unsuitable for web delivery, and HEIC files usually need to be converted to JPG, WebP, or AVIF before sharing online.

Best use cases

Use HEIC as the capture format on iPhone and iPad to maximize storage space and photo quality. When sharing HEIC photos online, via email, or with non-Apple users, convert them to JPG for compatibility or WebP/AVIF for web delivery. This site's HEIC to JPG converter can transform HEIC files to universally compatible JPG format entirely in your browser. Do not use HEIC for web images, as no browser supports it natively. For professional photography workflows that require 10-bit color or HDR, HEIC can be a useful intermediate format, but final delivery should use a web-compatible format like AVIF for the web or JPG/PNG for universal compatibility.

Formats

Other formats: TIFF, BMP, SVG

Specialized formats for print, legacy systems, and vector graphics.

TIFF

TIFF (Tagged Image File Format) is a flexible, lossless format widely used in professional photography, print, and archival workflows. TIFF supports 8-bit, 16-bit, and 32-bit color, multiple color spaces (RGB, CMYK, Lab), alpha channels, layers (in some implementations), and various compression methods including LZW, ZIP, and JPEG. TIFF files are large but preserve maximum quality, making them ideal for scanning, archiving, and print production. TIFF is not suitable for web use due to large file sizes and limited browser support. Use TIFF as a master or archival format, and export to JPG, WebP, or AVIF for web delivery.

BMP

BMP (Bitmap) is a legacy Windows format that stores uncompressed pixel data. BMP files are extremely large (a 1920x1080 BMP is over 6 megabytes) because they apply no compression. The format supports 1-bit, 4-bit, 8-bit, 16-bit, 24-bit, and 32-bit color, and optionally alpha transparency. BMP has no practical use in modern web or photography workflows and exists primarily for compatibility with legacy Windows applications. Never use BMP for web delivery or general image storage; convert to PNG, WebP, or JPG for dramatically smaller files with identical or better quality.

SVG

SVG (Scalable Vector Graphics) is an XML-based vector format that describes images as shapes, paths, text, and filters rather than pixels. SVG images can be scaled to any size without quality loss, are typically very small for simple graphics, and can be animated and styled with CSS. SVG is universally supported by all modern browsers and is the ideal format for logos, icons, diagrams, charts, and illustrations. SVG is not suitable for photographs, which must be stored as raster formats. For web use, inline SVG in HTML provides the best performance and accessibility, while external SVG files work well for reusable assets.

Reference

Format comparison summary

A quick reference comparing all major formats across key dimensions.

Compression and file size

Ranked from smallest to largest typical file size for photographic content at equivalent quality: AVIF (smallest), HEIC, WebP, JPG, PNG, TIFF/BMP (largest). For graphics and screenshots with flat colors: AVIF lossless, WebP lossless, PNG, TIFF, BMP. For animation: MP4 video (smallest), WebP animated, GIF (largest). The exact ratio varies by image content, but as a general rule, modern formats (AVIF, WebP) produce files 25 to 60 percent smaller than legacy formats (JPG, PNG) for equivalent visual quality. This directly translates to faster page loads and lower bandwidth costs.

Browser support

Universal support: JPG, PNG, GIF, SVG. Near-universal (95%+): WebP. Strong and growing (92-95%): AVIF. Limited/none: HEIC (no browser support), TIFF (partial), BMP (some). For web delivery, always provide fallbacks for formats with less than 100 percent support. The picture element allows you to list AVIF first, then WebP, then JPG or PNG, and the browser chooses the first format it supports. CDNs can automate this process through content negotiation based on the browser's Accept header.

Feature support

Transparency: PNG, WebP, AVIF, HEIC, GIF (1-bit only), SVG. Not JPG, BMP (optional). Animation: GIF, WebP, AVIF, HEIC, SVG. Not JPG, PNG. HDR and 10-bit+ color: AVIF, HEIC, TIFF. Not JPG (8-bit), PNG (up to 16-bit but no HDR), WebP (8-bit only). Lossless: PNG, WebP lossless, AVIF lossless, TIFF, GIF, BMP. Lossy: JPG, WebP lossy, AVIF lossy, HEIC, TIFF (optional). Vector: SVG only. Choose the format that supports the features your image requires while minimizing file size.

Decision

How to choose the right format

A practical decision framework for selecting the optimal image format for any use case.

For web delivery

For photographs on the web: use AVIF with WebP and JPG fallbacks for the smallest files and broadest support. If you want simplicity, use WebP with JPG fallback. For graphics, logos, and screenshots: use WebP or AVIF lossless with PNG fallback. For icons and simple illustrations: use SVG for infinite scalability and tiny file sizes. For animations: use looping MP4 video instead of GIF for dramatically smaller files. Always serve appropriately sized images for each device using srcset and sizes, and compress images to minimize file size without visible quality loss. The goal is the smallest file that looks excellent at the displayed size.

For editing and archiving

For photo editing: use a lossless master format like TIFF, PNG, or your editor's native format (PSD, XCF) during editing to avoid generation loss from repeated lossy saves. Export to JPG, WebP, or AVIF only as the final step for delivery. For archiving: use TIFF (lossless, widely supported) or RAW (camera native, maximum data) for long-term storage. For mobile capture: HEIC is the default on iPhone and offers excellent quality and storage efficiency. Never edit a JPG and re-save it as JPG repeatedly; each save degrades quality. Keep the original and export fresh copies from the master.

For sharing and email

For email attachments and general sharing: use JPG for photographs and PNG for graphics, as these are universally supported by all email clients and devices. Avoid HEIC, WebP, and AVIF for email, as many clients and older devices cannot display them. For social media: JPG is universally accepted, though most platforms now also support WebP and PNG. Always resize images before emailing to avoid oversized attachments; most email providers limit attachments to 25 MB. Use a file compression tool or resize the image to reduce dimensions and file size before sharing.

FAQ

Frequently asked questions

Quick answers to common questions about this topic.

What image format is best for web use?

For modern websites, WebP is the best overall format, offering 25-35% smaller files than JPG/PNG. Use JPG for photographs, PNG for graphics with transparency, and WebP as the primary format with fallbacks. AVIF offers even better compression but has less browser support.

What is the difference between JPG and JPEG?

There is no technical difference between JPG and JPEG. JPEG stands for Joint Photographic Experts Group, and JPG is simply the three-character file extension used by older Windows systems (which required 3-character extensions). Both refer to the same format and compression standard.

When should I use TIFF format?

Use TIFF for professional print work, archival storage, and images requiring multiple edits. TIFF supports lossless compression, multiple layers, CMYK color space, and high bit depths. File sizes are large, so TIFF is not suitable for web use. Convert to JPG/WebP for web delivery.

Is SVG good for website images?

SVG is excellent for logos, icons, and simple graphics. It is vector-based, so it scales infinitely without quality loss and has tiny file sizes. However, SVG is not suitable for photographs or complex images. Use SVG for UI elements and JPG/WebP for photos.

What is HEIC and why does my iPhone use it?

HEIC (High Efficiency Image Container) is Apple default photo format since iOS 11. It uses HEVC compression to store photos at roughly half the size of JPG with equivalent quality. It is not widely supported on web browsers, so convert to JPG/WebP before uploading to websites.