One format for a whole folder
Converting images one at a time is fine for a single picture, but not for a folder of 80 product photos or a year of phone pictures. A bulk image converter lets you select everything at once, pick one target format and get all the results in a single ZIP, with the original file names.
It's especially useful when the folder is a mix. Photos from an iPhone in HEIC, screenshots in PNG, images saved from websites in WEBP or AVIF, old scans in BMP or TIFF and camera RAW files can all go into the same batch and come out in one consistent format.
Common bulk jobs
Online stores: turn a whole catalog of product photos into WEBP or AVIF before uploading to Shopify, WooCommerce or WordPress, so pages load faster. Web developers: convert an assets folder to a modern format for a site that serves AVIF or WEBP with fallbacks. Office work: change dozens of images to JPG because the document system, the printer or a client's software only takes JPG. Photographers: get JPG copies of a full card of RAW files from the camera's own previews. Everyday users: make all the WEBP images saved from the web open in older Windows programs.
Whatever the output, the steps are the same: select the files, choose the format, download the ZIP.
Formats and honest limits
Input can be JPG, JPEG, JFIF, PNG, WEBP, GIF (first frame), BMP, AVIF, ICO, SVG, TIFF, PSD, Illustrator .ai, camera RAW and JPEG XL. HEIC works in Safari and in Chrome on devices with an HEVC decoder; if your browser can't open a file, you're told. RAW files use the preview stored by the camera, not a developed RAW.
Each output has its own behavior. JPG and BMP fill transparent areas with white. AVIF makes very light files but is slow to encode, especially on phones, so big AVIF batches are more comfortable on a computer. TIFF is uncompressed and heavy. ICO creates a square icon with several sizes. GIF is limited to 256 colors.
No upload, no limits
Bulk conversions on many websites mean uploading hundreds of megabytes and waiting. Here the images are converted in your browser, so nothing travels over the internet and your files stay private. There's no account, no watermark and no cap on the number of files; the only limit is your device's memory. If a very large batch feels slow, split it into two or three rounds.