Batch image resizer
Add several photos, resize them and convert to WebP, PNG or JPG. Processing runs in your browser without sending images to a server. Get a ZIP of the results or individual files.
upload · resize · convert
Resize and convert several photos
Add images, choose a resize mode and output format, then convert. Download available results as a ZIP or individual files. Photos are read in your browser without sending them to a server.
Drop images or click to add several files. Images are read and processed in your browser without sending them to a server.
Add images.How to use the batch image resizer
This tool resizes several images and converts them to WebP, PNG or JPG. Camera and phone images can be larger than needed for a blog, store or profile. Choose a width, percentage, bounding box or exact size, then compare output dimensions and quality before publishing. The file list shows the planned dimensions for each original. Keep the original images separately so you can return to full detail later.
Reading, resizing and format conversion run in your browser without sending the photos to Toolvil. Check source usage rights separately. Convert requests an individual download for each file. After processing, the ZIP button bundles available results into toolvil-images.zip. ZIP names support Korean, Spanish and emoji through UTF-8. If some images fail, check the result list and the number of files ready for ZIP.
When this tool is needed
- Resize product photos to a store width such as 1000px.
- Compare WebP output for images on a blog or website.
- Reduce a photo for an application or résumé, then check the actual file size against the destination limit.
Before converting
- Decide whether to keep the aspect ratio or force width and height without cropping.
- Choose PNG for lossless resized pixels and transparency, or compare WebP and JPG when file size matters.
- Test a few high-resolution images first and use small batches suited to your device.
How to use
- Drop images or click the add area to choose several files.
- Choose keep ratio, exact size, percentage or width mode.
- Enter width, height or percentage as needed.
- Choose WebP, PNG or JPG and the encoding quality.
- Press Convert / download files to request individual downloads. After conversion, Download ZIP bundles available results in one archive.
Choosing a resize mode
Keep ratio scales the whole image to fit the tighter width or height limit; it may also enlarge a small source. Exact size forces both dimensions, so a different ratio stretches or compresses the image rather than cropping it. Percentage scales relative to each original. Width mode calculates height from the original ratio. Each output edge is rounded and capped at 8000px, so check the listed dimensions when working near that cap.
Choosing WebP, PNG or JPG
WebP and JPG size and edge detail depend on the image and quality setting.80/90/100% are encoder settings;100% does not restore the original file or guarantee lossless output. PNG stores resized pixels losslessly and ignores the quality choice. PNG and WebP retain transparency; JPG flattens it onto white. This is not a tool for preserving animation, EXIF or camera metadata, so keep the originals separately.
Conversion method and output limits
Dimensions are rounded to whole pixels and each output edge is capped at 8000px. Check the listed size when very large images reach this cap, even in fit or width mode. The browser performs pixel interpolation and encoding, so bytes and quality may vary by browser and version. ZIP uses uncompressed storage with each file CRC-32 and UTF-8 name flags. Changing size, quality or format, or adding files, clears the previous ZIP results and requires another conversion.
This tool processes images in your browser without sending them to a server. Quality and file size depend on the source and selected size, format and quality. The ZIP button bundles available results after conversion. Individual downloads may require the browser to allow multiple downloads. A download request does not confirm that the operating system saved the file; check the browser download list.
FAQ
Does resizing reduce image quality?
Reducing size removes detail, and enlargement may look blurry. The 80/90/100% choices for JPG and WebP are encoder quality settings, not a promise to retain that share of original quality. PNG stores the resized pixels losslessly; it does not retain every original pixel or metadata field. Open the result and check text, edges and transparency.
Can I download the converted images as a ZIP?
Yes. After conversion, Download ZIP bundles available output images in toolvil-images.zip. The ZIP is created in your browser without an external library. Individual downloads remain available.
Why choose WebP?
WebP is an option to compare when reducing files for the web, and it supports transparency. Size and quality depend on the source and settings; it is not always smaller than JPG. Converting transparent images to JPG uses a white background. Check whether the destination service accepts the output format.
Are my photos sent to a server?
No. Reading, conversion and ZIP creation run in your browser. Toolvil does not send the original or results to its server or store them there. Local processing does not establish image usage rights; check that you have permission to use the source.
How many images can I convert at once?
There is no fixed file-count limit, but capacity depends on device memory and source size. Try a small batch first and split large originals into smaller groups. Each output edge is limited to 8000px. If the browser restricts multiple individual downloads, get the ZIP after conversion.