About the project
About TestFiles.dev
TestFiles.dev combines a browser-local test file generator with a small verified library of stable video and document fixtures for development and QA.
Why this library exists
Development teams repeatedly need known bytes to test a UI, API, upload limit, player, parser, or browser. TestFiles.dev generates image, WAV, WebM, and text fixtures locally while keeping the published video and document catalog intentionally small and predictable.
What the site provides
The local generator creates disposable fixtures without uploading them. The 13 published MP4, MOV, WebM, PDF, DOCX, XLSX, and PPTX assets have stable R2 URLs, documented MIME types, exact byte sizes, SHA-256 values, verification dates, copy-ready code, and dedicated detail pages.
Browser-local generation
Image, PCM WAV, WebM, and structured-text presets are assembled by browser APIs and downloaded from an in-memory Blob. The page does not send generated content to TestFiles.dev. Exact-size mode appends NULL bytes after a valid payload so upload boundaries can be exercised while common browser decoders continue to read the underlying file.
Deterministic inputs are used wherever the browser platform permits it. In particular, the audio sampler uses stable PCM generation and a fixed seed for white noise, which makes repeated downloads and waveform previews comparable during regression testing.
Published-file verification
Stable assets follow a separate release path. Source files are inspected with format-aware tools, normalized when necessary, hashed, and compared with committed metadata before they are published. Video checks cover container, codecs, frame rate, dimensions, duration, audio-track presence, playback, and HTTP byte ranges. PDF and Office checks cover signatures, container structure, page, sheet, or slide counts, and successful opening in compatible readers.
Browser and automation compatibility
The interface targets current Chrome, Safari, and Firefox. Native media controls remain available as an accessibility and compatibility fallback, and unsupported browser features return an explicit error instead of silently creating a different fixture. Stable download URLs are intended for Playwright, Cypress, cURL, and API tests that need reproducible remote inputs.
How to use it
Use the files as repeatable development fixtures. Do not treat a public sample URL as a service-level dependency for production user content. For automated suites that require permanent isolation, record the hash and mirror the file in your own controlled test environment.