Bulk Image Converter
Convert, resize, and compress many images at once in bulk — JPG, PNG, WebP, AVIF, and HEIC input, with AVIF output and HEIC to JPG batch conversion — then download them all as a ZIP. Everything runs in your browser, so your photos stay private.
All conversion runs in your browser with the Canvas API — images are never uploaded. Re-encoding also strips EXIF/location metadata.
Understanding the Bulk Image Converter
Bulk Image Converter processes many images at once: convert between formats (JPG, PNG, WebP, and more), resize to a target width or height, compress to shrink file size, then download everything as a single ZIP. It saves photographers, online sellers, bloggers, and developers from editing pictures one by one. Drop in a whole folder, set your options once, and get a packaged result. All conversion happens in your browser using the Canvas API, so original photos never leave your computer, which matters for product shots and personal images alike.
How it works
Each image is decoded and drawn onto an HTML Canvas element. The canvas is then exported with toBlob() in your chosen format and quality setting, which handles conversion and compression in one step; resizing happens by drawing to a smaller canvas before export. WebP and JPEG support an adjustable quality value, while PNG stays lossless. The finished blobs are gathered into a ZIP archive in-browser (commonly via JSZip) and offered as one download. Because everything runs locally in JavaScript, there are no uploads and no server limits. Very large batches use more memory, so split huge sets if your browser slows down.
Worked example
You have 60 product photos at 4000x3000 px PNG, around 8 MB each. You set output to WebP at 80 percent quality and a max width of 1200 px. The tool scales each image down proportionally to 1200x900, re-encodes it as WebP, and typically lands near 120 to 200 KB per file. Sixty images that started at roughly 480 MB collapse to about 10 MB total, bundled into one ZIP ready for a fast-loading store listing, all without uploading a single original.
Tips & common mistakes
- Use WebP for the best size-to-quality ratio on the web; keep JPG if you need maximum compatibility with older tools.
- Set a max width matching where images will display; resizing is the biggest size saver.
- Keep PNG only when you need transparency or lossless graphics like logos and screenshots.
- Quality around 75 to 85 percent is usually invisible to the eye while cutting size sharply.
- Process very large batches in smaller groups if the browser tab becomes sluggish or runs out of memory.
Related tools
How to Convert Images in Bulk
- 1Upload or drag in your images — add as many as you like.
- 2Choose the output format, and optionally set max dimensions and quality.
- 3Click Convert, then download all as a ZIP or save them one by one.
Frequently Asked Questions
Are my images uploaded to a server?
No. Every image is converted locally in your browser using the Canvas API. Your photos never leave your device, which also means it works offline once the page has loaded.
Which formats are supported?
Inputs can be JPG, PNG, WebP, AVIF, HEIC/HEIF, GIF, BMP, or SVG — mix any of them in one batch. Outputs are JPG, PNG, WebP, or AVIF, so you can do things like HEIC to JPG or convert to AVIF in bulk.
How do resize and quality work together?
Resize sets a maximum width and/or height (images keep their aspect ratio and are never enlarged). Quality controls compression for lossy formats (JPG and WebP) — lower quality means smaller files.
What happens to GIF and SVG inputs?
GIF and SVG files are accepted as input but are always converted to one of the four output formats (JPG, PNG, WebP, or AVIF). The result is a single static image — animated GIFs are flattened to their first frame, and SVG vectors are rasterized at their displayed size.
Can I download everything at once?
Yes. After converting, click "Download all (ZIP)" to get a single ZIP archive, or save images individually.