Image Formats Compared: JPEG vs PNG vs WebP

Choosing the right image format can make the difference between a fast-loading website and one that frustrates visitors. Each format was designed with specific strengths and trade-offs, and understanding these differences is essential for anyone who works with digital images. In this guide, we'll break down the four most common image formats — JPEG, PNG, WebP, and BMP — and help you decide which one to use in every situation.

Introduction to Image Formats

An image format defines how pixel data is encoded, compressed, and stored in a file. Different formats use different compression strategies, support different features (like transparency or animation), and produce different file sizes. There is no single "best" format — the right choice depends on the type of image, where it will be used, and what trade-offs are acceptable.

JPEG: Best for Photographs

JPEG (Joint Photographic Experts Group) has been the standard format for photographs since the early 1990s. It uses lossy compression, which means it reduces file size by discarding some image data that the human eye is unlikely to notice.

JPEG excels with photographs and images that have smooth gradients, complex colors, and natural scenes. A well-compressed JPEG can be 5–10 times smaller than the equivalent uncompressed image with minimal perceptible quality loss. Most digital cameras, smartphones, and social media platforms use JPEG as their default format.

However, JPEG has notable limitations. It does not support transparency — every pixel must have a solid color. It also struggles with images that have sharp edges, text, or flat areas of color, where compression artifacts become visible as blocky patterns or color banding. Each time a JPEG is edited and re-saved, additional quality is lost, making it a poor choice for images that will undergo multiple rounds of editing.

PNG: Best for Transparency and Graphics

PNG (Portable Network Graphics) was created as an improved replacement for GIF. It uses lossless compression, preserving every pixel of the original image exactly. This makes PNG ideal for situations where image fidelity is critical.

The standout feature of PNG is its support for full alpha transparency. Unlike JPEG, which fills every pixel with a solid color, PNG allows pixels to be partially or fully transparent. This makes it the go-to format for logos, icons, overlays, UI elements, and any graphic that needs to be placed on different backgrounds.

PNG also handles images with sharp edges, text, and flat colors exceptionally well. Screenshots, diagrams, illustrations, and graphics with text will look crisp and artifact-free in PNG format. The trade-off is file size — PNG files are typically much larger than equivalent JPEGs, especially for photographic content. A photograph saved as PNG can easily be 5–10 times larger than the same image as a JPEG.

WebP: The Modern Alternative

WebP is a modern image format developed by Google, designed to provide superior compression for both lossy and lossless images. It combines the best qualities of JPEG and PNG into a single, versatile format.

In lossy mode, WebP produces files that are typically 25–35% smaller than comparable JPEGs at the same visual quality. In lossless mode, WebP files are around 25% smaller than equivalent PNGs. WebP also supports transparency (in both lossy and lossless modes) and even basic animation, making it a true all-in-one format.

Browser support for WebP is now excellent, with all major browsers — Chrome, Firefox, Safari, and Edge — fully supporting the format. The only remaining consideration is legacy compatibility: older browsers and some native applications may not display WebP images. For web use, however, WebP is increasingly the best default choice.

BMP: The Uncompressed Format

BMP (Bitmap) is one of the oldest image formats, dating back to the early days of Windows. It stores pixel data with little to no compression, resulting in files that are extremely large compared to other formats.

A 1920×1080 photograph saved as BMP can easily exceed 5 MB, while the same image as a JPEG might be under 300 KB. BMP files preserve every pixel with perfect accuracy, but the massive file sizes make them impractical for web use, email, or any scenario where bandwidth or storage is a concern.

BMP still has niche uses in some legacy software, embedded systems, and situations where raw, uncompressed pixel data is needed for processing. For general-purpose image work, however, PNG provides the same lossless quality with dramatically smaller file sizes.

Which Format Should You Use?

Here's a practical decision framework to guide your format choice:

• Photographs for the web: Use WebP if your audience uses modern browsers. Fall back to JPEG for maximum compatibility. Aim for 70–85% quality for the best size-to-quality ratio.
• Logos, icons, and UI elements: Use PNG for its lossless quality and transparency support. Use SVG for vector graphics when possible.
• Graphics with transparency: Use PNG for lossless transparency or WebP for smaller files with transparency support.
• Social media images: Use JPEG or WebP. Most platforms will re-compress your images anyway, so start with a high-quality original.
• Email attachments: Use JPEG for photos (small file sizes) and PNG for screenshots or documents with text.
• Archival and editing: Use PNG or TIFF to preserve full quality. Avoid JPEG for master copies since each re-save degrades quality.
• Maximum compatibility: Use JPEG for photos and PNG for everything else. These two formats are universally supported across every browser, operating system, and application.

How to Convert Between Formats

Converting images between formats is a common task, whether you're optimizing for web performance, adding transparency, or ensuring compatibility with a specific platform. SnapTools makes this process simple and private.

Our Format Converter lets you convert between PNG, JPEG, WebP, BMP, and GIF instantly — right in your browser. Simply upload your image, select the target format, and download the converted file. Because all processing happens locally on your device, your images remain completely private. There are no uploads, no server processing, and no file size limits.

Whether you need to convert a BMP screenshot to a web-friendly JPEG, add transparency by converting to PNG, or shrink a large photo by switching to WebP, SnapTools has you covered. Try the Format Converter now and see how easy format conversion can be.