Batch Image Resizer & Converter

How to resize a batch of images

Choose up to 30 JPEG, PNG or WebP files. Set the width and height limits, choose “Fit inside box” or “Fill box,” and select an output format. Adjust quality for JPEG or WebP, then decide whether smaller originals may be enlarged. Select “Process batch” to begin.

Results appear one by one with the source filename, output dimensions, and generated file size. You can download an individual result or use “Download ZIP” when processing has finished. The ZIP contains successful outputs only, and the status message reports failed files so a partial batch is not mistaken for a complete export.

The output names include a sequence number, a cleaned version of the original filename, and the dimensions. That makes the results easier to identify and reduces filename collisions when different inputs share a name. The tool does not modify or rename your source files on disk.

Fit inside a box versus fill and crop

“Fit inside box” preserves the complete image and its aspect ratio. Width and height act as upper bounds. A landscape image fitted inside a 1,200 by 1,200 box may become 1,200 by 800, while a portrait may become 800 by 1,200. The tool does not add blank padding to make every result a square.

“Fill box” produces the box proportions and center-crops content outside that area. This can be useful for consistent thumbnail shapes, but the crop may remove a face, logo, or important object positioned near an edge. The tool uses a centered crop; it does not detect faces or offer individual focal-point adjustments.

When enlargement is disabled, small inputs are not scaled up to a larger box. In fill mode, the requested box is reduced proportionally when needed so the crop can be produced without enlarging the source. If you require exact output dimensions even for a small original, enable enlargement and inspect the quality of the result.

Choose JPEG, PNG or WebP output

JPEG is useful when the destination requires it and transparency is unnecessary. This tool fills transparent regions with white for JPEG output. That replacement is deliberate and should be considered when processing icons, logos, or cut-out images.

PNG preserves transparency but can produce larger files, especially for photographs. The quality control is labelled for JPEG and WebP because canvas PNG output does not use that value as a comparable lossy quality setting. Selecting PNG does not guarantee a smaller output than the original.

WebP is another option when the destination supports it. The tool checks whether the browser produced the requested MIME type; it does not silently label a fallback file with an unsupported extension. If an output format is unavailable in your browser, the affected file receives an error rather than a misleading download.

A practical website image preparation workflow

Start from the largest useful originals and decide the intended display size. If product cards use one consistent shape, a centered fill crop may be appropriate only when the subject is positioned safely. If the complete product or illustration must remain visible, fit mode is more suitable even when the resulting dimensions vary.

Choose the output format according to the receiving system. A marketplace, CMS, email system, and design application may accept different formats and limits. After resizing, inspect representative images and check the actual file sizes. Use the target-KB compressor when a destination imposes a specific byte limit rather than only pixel dimensions.

Keep a source folder separate from the exported batch. Repeated lossy conversion can discard information, so a later size change is better generated from an original than from an already compressed derivative. Nuo Pixel Solutions uses the same distinction between source assets and delivery assets when planning a maintainable content workflow.

Individual downloads, ZIP and stopping a batch

Each successful result is available through its own download link. This is useful when only one image needs to be checked or a ZIP download is inconvenient. The ZIP option packages the current successful results without reprocessing the images.

“Stop after current image” requests a stop between files. It does not interrupt an image encoder in the middle of its current operation. Any completed results remain available, and the final message identifies the batch as stopped. A failed input is listed with a reason while subsequent files continue where possible.

Changing the selected files or processing settings clears the previous output set. Run the batch again to generate files for the new settings. This prevents an old download from being presented as if it reflected a newly selected quality, crop mode, or dimension.

Limits, privacy and common problems

The batch supports 30 inputs with a combined source size of 100 MB. Each input is limited to 20 MB and 40 megapixels. Width and height settings range from 1 to 6,000 pixels, and the total successful output budget is 100 MB. A file that would exceed the output budget receives an explanation rather than being added silently.

Large decoded images can consume substantially more memory than their compressed file sizes suggest. If the page becomes slow, use fewer files or smaller dimensions. Files are processed sequentially, which avoids decoding the whole batch at once, but a large individual image can still be demanding on a phone.

The application reads selected files locally and uses canvas to generate outputs. JSZip, used to package downloads, is hosted with this site. The processing code does not upload the images to a resizing API. The surrounding WordPress page can still request normal assets and plugin resources, so local image processing should not be described as an entirely network-free webpage.

Frequently asked questions

More useful browser tools

Explore the Nuo Pixel Solutions utility collection for image, PDF and QR tasks. If your team needs a custom workflow or an application around file processing, tell us what you want to build.