Main Features
- Supports local batch image upload and folder import with one shared target file size.
- Supports entering the target size in KB or MB and converts it to bytes automatically.
- Supports side-by-side preview of the source image and the enlarged result.
- Supports processing the current image or all queued images, plus single download and ZIP export.
- Keeps the original extension and MIME type, which is useful for upload testing and placeholder assets.
How To Use
- Click Select Images or Select Folder, or drag images into the upload area.
- Enter the target file size and choose KB or MB as the unit.
- Click Process Current for one file or Process All for the full queue.
- Download the current result or export all processed files as a ZIP package.
Processing Logic
The tool reads the original image file as binary data, creates a larger byte array, writes the source bytes to the beginning, and pads the remaining space with empty bytes so the file reaches the target size.
This usually does not change visible pixels, but it does increase the file size directly, which makes it useful for upload validation, placeholder files, and compatibility checks.
Use Cases
- Testing minimum or maximum upload size rules on websites and APIs.
- Preparing placeholder images or demo assets that need a specific file size.
- Checking how systems, components, or storage services handle larger image files.
- Generating batches of test images that meet upload size requirements.
Notes
- The target size must be larger than the original file size or processing will fail.
- The tool supports target sizes up to 50 MB.
- Results keep the original extension and MIME type instead of converting formats.
- Output files are mainly for testing, placeholders, and upload validation, and may not be accepted by every third-party system after tail padding.
- All reading, padding, and exporting run locally in your browser with no server upload.
FAQ
Why does the result image look the same?
The tool only pads file bytes and does not rewrite visible pixel content, so most images look identical to the source.
Why does processing still fail after I enter a target size?
The most common reason is that the target is smaller than or equal to the source file size, or the target exceeds the 50 MB limit.
Can the processed image still be opened normally?
Most common image formats can still be opened, but the main purpose of this tool is file size expansion for testing and placeholder workflows.