Bulk Image Converter — Many Photos, One Format
Convert many images to a single chosen format in one drop. Mix JPG, PNG, WebP, BMP, TIFF, GIF, AVIF and HEIC inputs; the tool normalises every file in your browser and bundles the outputs into a ZIP.
Drop your JPG / PNG / WebP / BMP / TIFF / GIF / AVIF / HEIC / HEIF files hereTap to select files
Supports JPG, PNG, WebP, BMP, TIFF, GIF, AVIF, HEIC, HEIF, up to 200MB each
What to do next
Related tools
Compress Image
Reduce image file size while preserving visual quality.
imageResize Image
Resize images to exact dimensions or percentages.
imageImage to WebP
Convert images to the modern WebP format.
imageJPG to PNG
Convert JPG images to PNG format.
imagePNG to JPG
Convert PNG images to JPG format.
imageHEIC Batch Converter
Convert multiple HEIC and HEIF photos to JPG, PNG or WebP at once. The libheif decoder runs in your browser and the outputs are bundled into a single ZIP for one-click download.
imageAbout Bulk Image Converter
If you have a folder full of mixed-format images and you need them all in one consistent format — JPG for an email attachment, PNG for transparency, WebP for a fast-loading website — the Bulk Image Converter handles the entire job in one drop. Mix JPG, PNG, WebP, BMP, TIFF, GIF, AVIF and HEIC inputs freely. Pick a single target format. Download a ZIP of converted images.
Every conversion runs through the HTML5 Canvas API, which is the same engine that powers all the single-file converters in the catalog. HEIC inputs route through libheif first to obtain a JPEG intermediate (so the same decode quality as the dedicated HEIC tools), then go through the standard canvas path. JPG output gets a white background painted under any transparent pixels — a common pitfall with naive canvas exports — so transparent PNGs and WebPs convert to non-black-bordered JPGs. PNG output is fully lossless. WebP output defaults to 0.85 quality, configurable per run.
The processing model is sequential rather than parallel. WebAssembly decoders for HEIC and AVIF allocate significantly during a decode, and running multiple in parallel reliably crashes mobile browsers under any reasonable batch size. Sequential processing keeps memory usage bounded — the working set is one image at a time, regardless of batch size — and the per-image cost is so low that a 100-image batch finishes in under a minute on a modern laptop. The progress bar updates per file so the user sees clean visible movement.
Two design choices worth knowing. First, pixel dimensions are preserved exactly — the format is changed but the image is not resized. To resize as part of the batch, drop the output ZIP into Resize Image afterwards. Second, the input file's EXIF block is preserved on JPG and WebP outputs (PNG does not have a standardised EXIF location). If you need to strip EXIF deliberately for a public upload, run the converted files through EXIF Data Remover after the batch completes.
The tool is ideal for the boring-but-painful conversion tasks that come up regularly in real workflows: normalising a stack of camera-roll photos to JPG before emailing them, converting a mixed folder to WebP for a website's media library, or generating PNG copies of a TIFF archive for clients who do not have specialised viewers. It does the job in one shot, in the browser, with with all processing happening locally.
How it works
- 1Drop multiple images onto the upload area. Mix JPG, PNG, WebP, BMP, TIFF, GIF, AVIF and HEIC freely. Combined input up to 200 MB is accepted.
- 2Pick the target format — JPG (smallest for photos, no transparency), PNG (lossless, transparency), or WebP (modern, lossy or lossless).
- 3Optional: adjust the JPG/WebP quality slider if the default 0.92 / 0.85 setting is not what you want.
- 4Each file is decoded into a canvas. JPG outputs paint a white background under any transparent pixels first to avoid the common black-border issue.
- 5The canvas is re-encoded to the target format and packaged into a ZIP entry. Sequential processing keeps memory usage predictable.
- 6Download the ZIP. Filenames keep their base name with the new extension; pixel dimensions are preserved exactly.
Common use cases
- Normalise a mixed folder of phone, screenshot and downloaded images to JPG for one consistent email attachment
- Convert an archive of TIFF master scans to PNG copies for clients who do not have specialised viewers
- Prepare a website media library by converting every uploaded image to WebP for faster page loads
- Migrate a long-term photo archive from BMP and GIF to modern WebP for storage savings without quality loss
- Standardise product photography across a Shopify catalogue where images came from many sources in many formats
- Convert a stack of AVIF screenshots to JPG so they paste cleanly into a slide deck on Windows
FAQ
Which input formats are supported?
JPG, PNG, WebP, BMP, TIFF, GIF, AVIF, and HEIC/HEIF. You can mix formats freely in a single drop — the tool detects each file’s type and routes it through the appropriate decoder.
Which output format should I pick?
JPG for the smallest file size when you do not need transparency. PNG for lossless output that supports a transparent background. WebP when you want both transparency and small file size and you control the platform that will display the images.
How many files can I drop in?
Up to 200 MB combined. There is no hard cap on file count — the tool processes them one at a time so a folder of 500 small thumbnails is just as fine as a small batch of large camera photos.
Does it resize the images?
No — the format is changed but pixel dimensions are preserved exactly. To resize as part of the batch, run the output ZIP through Resize Image afterwards.
Will any of the images be uploaded?
No. Every conversion runs locally using the HTML5 Canvas API in your browser. HEIC inputs use libheif compiled to WebAssembly, also entirely client-side. The ZIP is built in memory.
Why does my JPG output have a white background instead of the transparent one in the source?
JPEG does not support transparency — it has no alpha channel. The tool paints a white background under any transparent pixels before the JPEG export so the image looks reasonable on any background. If you need to keep transparency, pick PNG or WebP as the target format instead.
Will it resize the images?
No — pixel dimensions are preserved exactly. Only the format is changed. To resize as part of the batch, drop the output ZIP into Resize Image afterwards.
Are EXIF data and GPS coordinates preserved?
EXIF passes through to JPG and WebP outputs intact. PNG does not have a standardised EXIF location, so on PNG export the EXIF block is dropped. If your goal is to strip EXIF deliberately, run the output through EXIF Data Remover.
Will my images be uploaded?
No. Every conversion runs locally — the HTML5 Canvas API does the encode, libheif compiled to WebAssembly handles HEIC inputs, and the ZIP is built in memory. The only network traffic is the initial JS chunk download, which is shared with every other image tool.
How is this different from the HEIC Batch Converter?
The HEIC Batch Converter accepts ONLY HEIC / HEIF inputs and is optimised for that single decode path with bounded concurrency. The Bulk Image Converter accepts every common image format including HEIC, but processes sequentially because parallelising mixed-format batches across mobile devices is fragile. Pick HEIC Batch Converter for an iPhone-only batch (faster); pick Bulk Image Converter for any mixed-format batch.
How many files can I drop in?
There is no hard count limit. The cap is 200 MB combined input. A folder of 500 thumbnails is just as fine as a small batch of large camera photos. Sequential processing means memory usage stays bounded regardless of count.
What if a file fails to convert?
The batch continues; failed files are listed in the metrics so you can see exactly which ones did not make it. Common causes are corrupted inputs and unusual codec variants the browser cannot decode natively.