Image Converter

What this image converter online does

This free image converter online lets you convert image files between PNG, JPG, WebP, and AVIF without installing any software and without uploading your files to a server. The conversion runs entirely in your browser using the HTML5 Canvas API: the tool decodes your source image, draws it onto a canvas, then exports the canvas pixels in your chosen format. You can drag in one image or many for batch conversion, adjust the quality slider for lossy formats, and download each result with one click. Because nothing leaves your device, the tool is safe for screenshots of internal dashboards, client photos, or any image you prefer to keep private. If you have been looking for a fast, private image format converter that handles the four main web formats, this page is built for that job.

What is PNG and when should you use it?

PNG (Portable Network Graphics) is a lossless raster format, meaning it preserves every pixel exactly as it was when the file was saved. It supports full 24-bit colour plus an 8-bit alpha channel for transparency, making it the right choice whenever you need clean edges around a logo, an icon with a transparent background, or a screenshot of text where sharpness matters more than file size. PNG compression is lossless so re-saving a PNG never degrades it, which also makes it a reliable archival format. The trade-off is that PNG files are larger than their JPG or WebP equivalents for photographic content. A photo saved as PNG can be three to five times larger than the same photo saved as a high-quality JPG, which is why PNG is best reserved for graphics, illustrations, and screenshots rather than photographs.

What is JPG and when should you use it?

JPG (also written JPEG) uses lossy compression to store photographic images efficiently. It analyses the image and discards detail that the human eye is least likely to notice, which is why a JPG photo can be ten times smaller than a PNG of the same image while looking nearly identical at normal viewing sizes. The compression amount is controlled by a quality setting: higher quality means less data discarded and a larger file, lower quality means more data discarded and a smaller file. JPG does not support transparency, so any transparent pixels are replaced with a solid background colour on export. JPG is the right choice for photographs, camera images, and any image with complex gradients where the small size matters more than pixel-perfect accuracy. It is also the most universally supported format, readable by every browser, email client, and operating system without exception.

What is WebP and why does it make websites faster?

WebP is a modern image format developed by Google and released in 2010. It supports both lossy and lossless compression modes as well as transparency and animation, making it a single format that can replace both JPG (for photos) and PNG (for graphics with transparency). The lossy mode is based on the same technology as VP8 video encoding, and at equivalent visual quality it typically produces files 25 to 35 percent smaller than JPG. The lossless mode is about 26 percent smaller than equivalent PNG files. All major browsers have supported WebP since 2020, including Chrome, Firefox, Edge, and Safari 14 and later, so it is now safe to use as the primary format for website images. Converting your site images from JPG and PNG to WebP with this WebP converter is one of the quickest wins for page speed and Core Web Vitals scores.

What is AVIF and how does browser support work?

AVIF is a modern image format based on the AV1 video codec, standardised by the Alliance for Open Media. It achieves even better compression than WebP, often 30 to 50 percent smaller than an equivalent JPEG at the same perceived quality. AVIF supports a wide colour gamut, HDR, transparency, and both lossy and lossless modes. Decoding AVIF is now supported in Chrome, Edge, Firefox, and Safari 16.4 and later, which covers the vast majority of users. Encoding AVIF from a browser canvas is a newer capability: Chrome and Edge support it, but Firefox and Safari may not encode AVIF through the canvas API in all versions. This tool detects AVIF canvas encoding support at runtime and shows the AVIF option only when your browser can produce it. If you need guaranteed AVIF output across all environments, a command-line tool like Squoosh CLI or libavif is a more reliable choice.

Lossy vs lossless compression: what is the difference?

Lossless compression reduces file size by encoding repeated patterns more efficiently without throwing away any image data. When you decompress a lossless file you get back every original pixel exactly. PNG and WebP lossless use this approach. Lossy compression goes further by discarding image data that perceptual models predict the eye will not miss, which is why a lossy file can be dramatically smaller. JPG, WebP lossy, and AVIF lossy all use this approach. The risk with lossy compression is generation loss: each time you re-encode a lossy image, another round of data is thrown away. For this reason, you should always start conversions from the highest-quality source you have, and avoid converting between two lossy formats repeatedly. If you need to edit and re-save an image many times, keep a lossless master and export a lossy version only as the final step.

Transparency support across image formats

Transparency is controlled by an alpha channel, which stores a per-pixel opacity value alongside the colour data. PNG supports full 8-bit alpha, meaning each pixel can be anywhere from fully transparent to fully opaque with 256 steps in between. WebP supports alpha in both its lossless and lossy modes, making it a good format for transparent graphics on the web. AVIF also supports alpha when the browser encoder supports it. JPG has no alpha channel at all. When you convert a PNG with transparency to JPG using this tool, the transparent pixels are composited onto a white background, which is the standard convention. If you need to preserve transparency, choose PNG, WebP, or AVIF as your output format.

Converting screenshots: PNG to JPG and PNG to WebP

Screenshots are almost always saved as PNG by the operating system, which produces a large but perfectly sharp file. If you need to share a screenshot in an email, attach it to a document, or post it online, converting it to JPG or WebP will significantly reduce the file size. For most screenshots with text and UI elements, a JPG at quality 85 or a WebP at quality 80 looks virtually identical to the original PNG but is two to four times smaller. Converting PNG to WebP is an especially good choice for screenshots that will appear on a web page, because WebP is understood by all modern browsers and will improve page load speed compared to an equivalent PNG. Use this image converter to do both conversions in seconds without any software installation.

When to convert to PNG vs JPG: a practical guide

Choose PNG when your image has text, line art, a logo, an icon, a diagram, or any element with a transparent background. PNG keeps hard edges sharp because it never discards pixel data. Choose JPG when your image is a photograph, a product shot, or any scene with complex gradients and textures where some detail loss is acceptable in exchange for a much smaller file. A practical rule is: if the image came from a camera, use JPG. If the image was drawn, exported from a design tool, or captured as a screenshot of a user interface, use PNG. WebP can replace both for web use because it handles both use cases well, though at the cost of very slightly longer encoding time.

How browser-based conversion keeps your images private

Because this image converter runs entirely in your browser, your files never travel over the network to a server. The conversion happens on your own hardware using JavaScript and the HTML5 Canvas API. This matters whenever you are working with images that contain sensitive information: screenshots of internal systems, medical images, financial documents saved as images, client brand assets under NDA, or personal photos. Many online image tools route files through a backend server where they may be stored temporarily. This tool does not. Once the page has loaded you can disconnect from the internet and the converter will still work, which also makes it useful when you have a slow or unreliable connection.

Why WebP and AVIF matter for Core Web Vitals

Google's Core Web Vitals are the main page experience signals used in search ranking, and images directly affect two of the three: Largest Contentful Paint (LCP) and Cumulative Layout Shift (CLS). Serving images in WebP instead of JPG or PNG reduces their download time, which improves LCP scores. Serving AVIF reduces file sizes even further for browsers that support it. Many website auditing tools including Google PageSpeed Insights and Lighthouse flag unoptimised image formats as one of the highest-impact opportunities for improvement. Converting your key images to WebP with this webp converter is a free, one-time action that can meaningfully improve your search rankings and user experience without touching your code.