Generate a sample WebP image
Choose a target size for a WebP upload fixture and preview the decoded image. For odd byte targets, check RIFF alignment in your own validator.
1 MB = 1,000,000 B · 1 MiB = 1,048,576 B
Advanced: test an upload limit
Enter the byte limit above, then choose one byte below, the exact limit or one byte above. Each choice uses the same base: 10,485,760 B. Generate and download each file to test your endpoint.
WebP, built to spec.
Each file is a WebP image encoded by your browser. The size you ask for is reached with a custom RIFF chunk, with the container size field corrected afterwards, so the result opens in modern browsers, Photoshop 23+ and libwebp tools. Most people generate these for testing next-gen image delivery and format negotiation.
Choose a size here
These options set the generator above. Separate size guides explain how to test a particular upload boundary.
Guides for specific upload limits
File structure and testing limits
A generated image in a RIFF container with an extra chunk for padding. RIFF chunk alignment can add one byte after the container for some odd targets; strict validators may differ.
Format reference: WebP RIFF container.
This generator assembles the file in your browser; file content is not sent to a server. Site analytics may make network requests. Office ↔ PDF conversion uses a separate server workflow. Data processing and privacy.
Measured regression fixture (2026-10-13): 1,048,576 bytes. Validation method and limits.
Technical notes for every format · Guide to testing file upload limits
Related tools: Image Convert · Resize Image · Compress Image.
Questions
How small can a WebP file be?
About 1,309 bytes. Below that the format cannot carry its mandatory structure, let alone padding.
Will the file open normally?
Validate the generated fixture in your target application. Parts added for exact size may change or disappear when the file is re-saved; compatibility depends on the reader.
Can I ask for an unusual size?
Any byte count above the minimum works — for example 3,145,728 bytes (exactly 3 MB) or 27.5 MB. Drag the caliper or type the number.
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