Image Converter
Convert images between JPG, PNG, WebP, GIF and BMP — free, instant, browser-based
Conversion Settings
Output Format
Upload Images to Convert
Drag & drop or click to browse • Multiple files supported
Free Online Image Converter — Convert JPG, PNG, WebP, GIF and BMP Instantly
Getting an image file in the wrong format is one of the most common — and most frustrating — digital problems. A website only accepts PNG. Your email client won't attach a TIFF. Your app needs WebP but you only have JPEG. You downloaded a BMP from a Windows tool and nothing opens it on your Mac. These situations happen to everyone, every day.
The OmniWebKit Image Converter solves the problem in three clicks. Upload one or more images, choose your output format (JPEG, PNG, WebP, GIF, or BMP), and download the converted files immediately. The entire conversion runs in your browser using the HTML5 Canvas API — your images never touch a server.
You can batch-convert multiple images at the same time, with all files converting in parallel. Each file shows a before/after size comparison so you can see exactly how the format change affected the file size. For JPEG and WebP outputs, a quality slider lets you control the trade-off between file size and visual quality.
Image Format Guide — When to Use Each Format
JPEG (JPG) — The Photography Standard+
JPEG is the most widely supported image format in the world. It uses lossy compression, which means it discards some image data to achieve small file sizes. A typical high-resolution photograph can be stored at 200–500 KB as a JPEG versus 5–10 MB as an uncompressed image. The quality setting controls how aggressively data is discarded — at 85–95%, the difference from the original is invisible at normal viewing distances. JPEG does not support transparency.
✓ Best for
Photographs, social media images, blog post images, email attachments, product photos
✗ Avoid when
Logos, icons, screenshots, anything with sharp text or flat colour areas
PNG — The Lossless Choice+
PNG uses lossless compression, which means no visual information is ever discarded. Every pixel is preserved exactly as stored. PNG also supports full alpha-channel transparency, making it the standard for web graphics, logo delivery, and UI elements that need to sit on top of different backgrounds. The downside: PNG files for photographs are dramatically larger than JPEG (often 5–10× larger).
✓ Best for
Logos, icons, screenshots, user interface elements, images with transparency, graphics with text
✗ Avoid when
Photographs and large images where file size matters — PNG files are much larger than JPEG for photographic content
WebP — The Modern Web Format+
WebP is Google's open image format, designed specifically for the web. It produces files 25–35% smaller than JPEG at equivalent visual quality, and 20–30% smaller than PNG for lossless images. It supports both lossy and lossless modes, and full transparency (like PNG). All modern browsers — Chrome, Firefox, Safari 14+, Edge — support WebP natively. Using WebP instead of JPEG or PNG on your website can measurably improve Core Web Vitals scores and page load speed.
✓ Best for
Website images, web banners, blog posts, landing pages, any image displayed in a modern browser
✗ Avoid when
Email clients that don't support WebP, legacy systems, print workflows
GIF — Animation Support+
GIF (Graphics Interchange Format) is one of the oldest image formats still in active use, and its persistence is almost entirely due to animation support. A GIF can store multiple frames that play in sequence, creating simple looping videos. The major limitation is the 256-colour palette — gradients look banded and photographs look terrible in GIF. For non-animated graphics, PNG is always superior.
✓ Best for
Simple animations, reaction images, memes, basic looping graphics
✗ Avoid when
Photographs (GIF is limited to 256 colours), anything requiring accurate colour reproduction
BMP — Windows Native Uncompressed+
BMP (Bitmap) is the native image format for Windows. It stores pixel data with no compression at all, which means file sizes are enormous — a 1920×1080 image will be about 6 MB as a BMP versus 200–500 KB as JPEG. BMP is only necessary when working with older Windows software that cannot handle other formats, or specific legacy print workflows. For all modern uses, JPEG, PNG, or WebP are better choices in every dimension.
✓ Best for
Legacy Windows applications, print workflows that require uncompressed input, very specific compatibility requirements
✗ Avoid when
The web, email, any modern use case — BMP files are extremely large and offer no advantages for typical use
How Does Image Format Affect File Size?
File size is the most visible difference between image formats, but it's not the only one that matters. Here's what actually happens when you convert between formats, and what to expect in terms of size changes.
| Conversion | Expected size change | Quality change |
|---|---|---|
| PNG → JPEG | 60–80% smaller | Minor loss (lossy encoding) |
| PNG → WebP | 20–40% smaller | No loss (lossless mode) |
| JPEG → PNG | 3–8× larger | No additional loss |
| JPEG → WebP | 25–35% smaller | Minimal loss (lossy mode) |
| JPEG → GIF | Similar or larger | Significant colour reduction |
| Any → BMP | 5–15× larger | No loss (uncompressed) |
Note: "No additional loss" means no new quality is removed during conversion — but any loss from previous JPEG compression is already baked in. Converting JPEG → PNG will not restore lost detail; it only stops further degradation.