Batch processing and watermarking guide
Compress, convert, resize, crop, transform, filter or watermark media on your device. Start with a small image, inspect the result, then use the same settings on your batch.
Open the processing workbench · Download a fictional sample image
Updated September 14, 2026. This guide describes the current workbench at /app.
Watermark a batch of images
- Download the sample image above, open the workbench, and choose Add files. You can also drag files into the queue.
- In Settings, choose Apply to → All files for a shared recipe, or This file to change only the selected item.
- Open Watermark. Choose Text and enter your watermark, or choose Image and select a logo file.
- Adjust Size, Opacity and Position. Text also has color and background controls. Inspect the preview; you can drag the watermark or select an anchor.
- Choose Process. Wait for completion, then use the download button to save the finished file or the batch ZIP. A preview alone does not export a file.
Download the real watermarked result. This sample uses text SAMPLE, size 28%, opacity 70%, a black background at 40%, and the bottom-right position. It was exported by the workbench on September 14, 2026.
Adding a watermark can increase file size. Inspect the output size and appearance; compression does not guarantee a smaller result for every file.
Watermark settings apply to images and video. Audio has no visual watermark. The Transform rotation control rotates the media frame; there is no separate watermark-angle setting.
File limits and the one-time licence
Free batches process the first 3 files. The $19 USD one-time licence removes the batch-count limit.
Every file must be at most 200 MiB (209,715,200 bytes), including with a licence. The interface labels this as 200 MB. A 1 GB video exceeds this limit. Large or high-resolution files may also exceed browser memory even below the file-size ceiling.
Processing speed depends on the file, codec, device and browser. Video and audio processing load a WebAssembly encoder on first use, so the first run can take longer. Keep the tab open while it loads and processes.
How output filenames work
BatchCrunch adds -crunched to the original filename stem and uses the output extension. For example, photo.png converted to WebP becomes photo-crunched.webp.
There is currently no Rename panel, custom filename template, or sequential numbering control. If you need a naming pattern, rename the saved results afterward. Your input files are not overwritten by processing.
Supported files and recovery
The file picker accepts JPEG, PNG, WebP, AVIF, MP4, WebM, MP3, WAV and M4A. Decoding still depends on the codec inside the file and your browser. An accepted extension does not guarantee that every variant can be processed.
- File too large: choose a smaller file or shorten/compress it with another tool before importing.
- Engine does not start: reconnect if assets have not finished loading, then reload and retry with a small file.
- Decode or encoding fails: try another supported output format or a shorter clip. Check the result before running a large batch.
What “local processing” means
Your selected media is processed inside your browser. The site still needs network requests for page assets, encoder downloads, checkout, licence redemption and feedback. Usage or hosting telemetry is separate from sending your media for processing.
To inspect this, open your browser’s Network panel, process the fictional sample and examine outgoing requests. The privacy meter is a diagnostic for request bodies the page observes; it is not a packet capture of all browser traffic. See privacy details.