Complete Guide to Image Formats — JPEG, PNG, WebP, HEIC, SVG, and More

Why Image Formats Matter

Every image on your computer, phone, or website is stored in a specific format — and that format determines how the image looks, how large the file is, what features it supports, and where you can use it. Choosing the wrong format means bloated file sizes, lost quality, missing transparency, or broken compatibility.

This guide covers the formats you will actually encounter: JPEG, PNG, WebP, HEIC, GIF, SVG, TIFF, AVIF, and BMP. For each, you will learn what it does well, where it falls short, and when to use it.

JPEG (JPG)

JPEG is the default format for photographs. It uses lossy compression — it permanently discards visual information to reduce file size. At high quality settings (85-95%), the loss is nearly invisible. At low quality settings (below 50%), you see blocky artifacts, especially around sharp edges and text.

• Best for: Photos, images with smooth gradients, web images where file size matters
• Not for: Text, logos, screenshots, anything needing transparency
• Transparency: No
• Animation: No
• Typical use: Camera photos, email attachments, social media uploads

PNG

PNG uses lossless compression — no quality is lost, ever. The file is larger than an equivalent JPEG, but the image is pixel-perfect. PNG also supports transparency (alpha channel), making it the standard format for logos, icons, and any image that needs to overlay other content.

• Best for: Screenshots, logos, icons, diagrams, text-heavy images
• Not for: Large photographs (file size will be excessive)
• Transparency: Yes (full alpha channel)
• Animation: No (APNG exists but has limited support)
• Typical use: App icons, web graphics, UI mockups, product images with transparent backgrounds

WebP

WebP is Google's modern image format that supports both lossy and lossless compression, transparency, and animation — all in one format. Lossy WebP files are typically 25-35% smaller than equivalent-quality JPEGs. Lossless WebP files are about 25% smaller than PNGs. It is now supported by all major browsers and most image editors.

• Best for: Web images (photos, graphics, and icons), replacing both JPEG and PNG online
• Not for: Print workflows (limited support in print software), archival (newer format with less universal support)
• Transparency: Yes
• Animation: Yes
• Typical use: Website images, Progressive Web Apps

For a detailed comparison, see our WebP vs PNG vs JPG comparison.

HEIC (HEIF)

HEIC (High Efficiency Image Container) is Apple's default photo format since iOS 11. It uses the HEVC video codec for compression, producing files roughly half the size of equivalent-quality JPEGs. The problem: outside the Apple ecosystem, support is patchy. Windows requires a codec extension, many web services reject HEIC, and most image editors do not handle it natively.

• Best for: Storing photos on iPhones and iPads (space savings)
• Not for: Sharing with non-Apple users, uploading to websites, email attachments
• Transparency: Yes (rarely used in practice)
• Animation: Yes (Live Photos)
• Typical use: iPhone camera output

Need to convert HEIC? Convert HEIC to JPG or HEIC to PDF for documents.

GIF

GIF is a legacy format that survives almost entirely because of animation. It supports simple frame-by-frame animation with a 256-color palette. The limited color depth makes it terrible for photographs but acceptable for simple graphics, UI demos, and short clips. For most animation purposes, WebP and MP4 video are better alternatives with smaller file sizes and more colors.

• Best for: Short animations, memes, simple UI demos
• Not for: Photos, anything needing more than 256 colors
• Transparency: Binary only (fully transparent or fully opaque, no semi-transparency)
• Animation: Yes (the format's primary reason to exist in 2025)

SVG

SVG is a vector format — instead of storing pixels, it stores mathematical descriptions of shapes (lines, curves, fills). SVGs scale to any size without losing quality, making them perfect for logos, icons, and illustrations. They are also text-based (XML), so they can be styled with CSS and manipulated with JavaScript on web pages.

• Best for: Logos, icons, illustrations, charts, diagrams
• Not for: Photographs or any raster image (use JPEG/WebP)
• Transparency: Yes
• Animation: Yes (CSS/JavaScript)
• Typical use: Website icons, brand logos, data visualizations

TIFF

TIFF is a professional format used in photography, publishing, and printing. It supports lossless compression, multiple layers, and very high color depths (16-bit and 32-bit per channel). Files are large — often 10-50x bigger than a JPEG — but no quality is sacrificed. TIFF is the standard format for professional photographers delivering to clients and for pre-press print workflows.

• Best for: Professional photography, printing, archival
• Not for: Web, email, or any context where file size matters
• Transparency: Yes
• Animation: No

AVIF

AVIF is the newest mainstream format, based on the AV1 video codec. It offers the best compression efficiency of any current image format — producing files 50% smaller than JPEG and 20% smaller than WebP at the same quality. Browser support is growing (Chrome, Firefox, Safari 16+) but not yet universal. Encoding is slow compared to JPEG and WebP.

• Best for: Cutting-edge web performance, large photo galleries
• Not for: Contexts requiring universal compatibility
• Transparency: Yes
• Animation: Yes

BMP

BMP (Bitmap) stores raw pixel data with minimal or no compression. Files are very large. There is virtually no reason to use BMP in modern workflows. If you encounter one, convert it to PNG (lossless) or JPEG (smaller) immediately.

Format Comparison Table

How to Choose

Follow these decision rules:

1. Is it a photograph? Use JPEG for general sharing, WebP for web, AVIF for maximum compression, TIFF for professional delivery.
2. Does it need transparency? Use PNG for static images, WebP for web with transparency, SVG for scalable graphics.
3. Is it a logo, icon, or illustration? Use SVG if possible (vector), PNG as fallback (raster).
4. Is it for the web? WebP first, AVIF if browser support allows, JPEG as universal fallback.
5. Need to convert? Use FileKit's image converter to switch between formats instantly in your browser.

Converting Between Formats

Format conversion is a daily task. Common conversions and when they make sense:

• HEIC → JPG: Sharing iPhone photos with non-Apple users. Convert here.
• PNG → WebP: Optimizing website images for faster loading.
• Images → PDF: Compiling photos into a single document. Convert here.
• PDF → Images: Extracting pages as images for presentations. Convert here.

When converting, remember: you cannot add quality that does not exist. Converting a low-quality JPEG to PNG does not make it higher quality — it just makes the file larger. Always start from the highest-quality source available.