Why are there so many image formats?

Each image format makes a different trade-off between file size, quality, and features such as transparency, so the right one depends on where the image goes. Converting also helps when a program or website won't take the format you have.

Format Transparency Good for
PNG Yes Screenshots, logos, and graphics with text, stored without losing detail
JPG No Photos, in small files with lossy compression
WebP Yes Web images, with lossy or lossless compression
GIF On or off per pixel Simple graphics with up to 256 colors
BMP Rarely Older Windows programs; the files are usually uncompressed and large
ICO Yes Windows icons and website favicons, with several sizes in one file
TIFF Yes Printing, scanning, and archiving
HEIC Yes Photos from iPhones and iPads; can be converted from, not to
AVIF Yes Modern web images with strong compression; can be converted from, not to
SVG Yes Vector logos and icons that scale to any size; can be converted from, not to

Tool description

This tool converts images between PNG, JPG, WebP, GIF, BMP, ICO, and TIFF, and from HEIC, AVIF, and SVG to any of those. Every image converter here works the same way, from the general Image Converter to the ones for a single pair, such as HEIC to JPG, PNG to JPG, or SVG to ICO: it starts on the formats in its name, and the Source and Target menus switch to any other. It converts one image or many at once. Browse files lists only images in the source format, but images dropped on it can be in any of them, and each one converts from its own format, so a WebP file converts even on the PNG to JPG converter. The Quality, Max Size, and Background options in Settings, under the target format, can make the images smaller or fill their transparent areas, and each image converts again as soon as you change one. Every converted image shows up in a grid with its own Download button: click one to see it full size. Converted images keep their original file names with the new extension.

Images are converted on your device and never uploaded.

Convert many images at once

Pick or drop as many images as you like, and add more at any time: this is a batch image converter, so there's no need to convert photos one by one. Bulk-convert iPhone HEIC photos to JPG, a set of PNG screenshots to WebP, or product photos to smaller JPGs with a lower Max Size, in one go.

  • The images convert one after another, in the order they were added, and the progress bar counts them.
  • They show up in a grid, each with its own Download button. Click a thumbnail to see the image full size, and use the arrows or swipe to go through the rest.
  • Download All saves every converted image in one ZIP file, or a single converted image as it is.
  • When two images would get the same name, a number is added to the later one, as in photo (1).jpg.
  • If an image can't be converted, an error message names it, and the others still convert.

Settings

  • Quality sets how much detail a JPG or WebP keeps, from 100% down to 10%. Each value is marked High, Medium, or Low: lower ones make smaller files with blurrier, blockier details. JPG and WebP start at 90%. For GIF, Quality sets how many colors the image gets, from 256 down to 16, starting at 256. PNG, BMP, ICO, and TIFF keep every pixel as it is, so their Quality shows Lossless and can't be changed. Chrome saves a WebP at 100% losslessly.
  • Max Size scales an image down until its longest side has at most that many pixels, keeping its shape: at 1920 px, a 4032 × 3024 photo becomes 1920 × 1440, and one taken upright becomes 1440 × 1920. An image that is already as small keeps its size, as scaling it up would only blur it. Original keeps every image at its own size. ICO files take their sizes from the checkboxes instead, so Max Size stays at Original for them.
  • Background sets the color that transparent areas get: Transparent keeps them, and White or Black fills them. JPG and BMP can't hold transparency, so they offer only White and Black and start on White, and a format picked after them that holds transparency starts over on Transparent.
  • When converting to ICO, check the icon sizes to include, from 16 × 16 to 256 × 256 pixels; all of them are checked to begin with.

How it works

The browser decodes the image, except TIFF, which UTIF.js decodes, and HEIC, which libheif decodes. The tool draws it on a canvas at the size Max Size allows, over the Background color. The browser then encodes PNG, JPG, and WebP files, gifenc writes GIF files, UTIF.js writes TIFF files, and the tool itself writes BMP and ICO files.

  • A GIF gets the colors that best match the image, as many as Quality allows. Pixels that are less than half opaque become transparent, unless a Background fills them, and the rest fully opaque.
  • An ICO file gets one square PNG image per size. An image that isn't square is scaled to fit and centered, with transparent margins, or margins of the Background color.
  • TIFF files are written uncompressed. Most browsers can't show TIFF, so the grid shows the original image when the target is TIFF.
  • A HEIC photo is turned and mirrored the way the file says, so it comes out upright. Only the main image of a HEIC file that holds several is converted. HEIC files take a moment longer, as libheif decodes them in the browser, and the first one downloads it.
  • An SVG is drawn at the width and height set in the file, or at the size of its viewBox, or at 300 × 150 pixels if it has neither.
  • Only the first frame of an animated GIF, WebP, or PNG is converted, and only the first page of a multi-page TIFF.
  • Metadata, such as the camera details and GPS location in a photo's EXIF data, isn't copied to the new file.

Tips

  • To keep a transparent background, convert to PNG, WebP, ICO, TIFF, or GIF rather than JPG or BMP.
  • For photos, JPG and WebP files are much smaller than PNG. For screenshots and logos, PNG keeps text and edges sharp.
  • To share or upload iPhone photos where HEIC isn't accepted, convert them to JPG.
  • To make photos smaller for email or the web, pick a lower Max Size, such as 1920 px, or a Medium Quality.
  • For a favicon, start from a square image of at least 256 × 256 pixels, or from an SVG.
  • To get a larger image from an SVG, raise its width and height attributes in a text editor first, since it's drawn at its own size.
  • An SVG that links to fonts or images in other files is drawn without them, because browsers don't load outside files for an image. Convert its text to paths and embed its images before converting.
  • Saving WebP needs a browser that can encode it. Other browsers show an error.