Free Online Screen Recorder
Record in up to 4K — export as MP4. Right in your browser. Nothing uploaded, ever.
Recording Settings
Audio Sources
Saved Recordings
Finished recordings stay saved in this browser only — nothing leaves your device. Refresh, close the tab, come back later: they're still here until you delete them.
No saved recordings yet.
🎬 Preview & Download
Bug bounty & security research
Record a vulnerability PoC with zero network calls, blur adjacent secrets before sharing, and attach a SHA-256 checksum to your submission for chain-of-custody.
Regulated & client work
Capture screen recordings with sensitive data without it ever leaving the device — useful under NDAs, GDPR, HIPAA-adjacent workflows, or strict client IT policy.
Air-gapped & offline environments
Load the page once, then disconnect entirely — recording, redaction, conversion, and hashing keep working with no connection at all.
More ways to use ScreenRec
Frequently Asked Questions
Why couldn't I scrub the timeline on downloaded recordings before?
The browser's MediaRecorder API writes WebM files without knowing the final duration in advance, so the file header is left with an undefined duration and no seek index — players have nothing to map a scrubber position to, so dragging or hovering the timeline does nothing. Every recording is now remuxed to MP4 through FFmpeg.wasm the moment you stop recording — entirely on-device — which builds a proper seek index and gives you maximum compatibility with players and editing software.
How do I know nothing is actually being uploaded?
Click the request counter in the top-right corner at any time — it's read live from your browser's own Performance API, the same data your browser's developer tools use, not something we control. You can also open your browser's Network tab and record a session yourself; you'll see no requests carrying video data at any point.
What does the redaction tool actually do?
After you stop recording, click "Blur sensitive areas," drag boxes over anything you don't want visible (API keys, internal hostnames, personal data), then apply. The tool replays your footage onto a canvas, paints solid blocks over the marked regions on every frame, and re-encodes — all in your browser. The unredacted footage never leaves your device, and the redaction is permanent in the output file, not just an overlay.
What's the SHA-256 checksum for?
It's a unique fingerprint of your exact output file, computed on-device using your browser's built-in SubtleCrypto API. If you're submitting a recording as evidence — for a bug bounty report, an incident writeup, or a compliance record — sharing this hash alongside the file lets anyone verify it hasn't been altered since you generated it, without needing a server to issue or check it.
Is the MP4 conversion done on a server?
No. FFmpeg.wasm runs entirely inside your browser as a WebAssembly module. Your video never leaves your device at any point.
How long does MP4 conversion take?
For a remux-only conversion (no re-encoding), it typically takes 5–30 seconds depending on recording length and your CPU. A 10-minute recording usually converts in under 20 seconds.
What is the MP3 option for?
MP3 extracts only the audio track — useful for recording a podcast, webinar, or meeting audio without the video. The video track is discarded and only the audio is saved as an MP3 file.
Which browsers are supported?
Chrome 72+ and Edge 79+ are fully supported for recording. MP4/MP3 export, trim, and caption burn-in run on a single-threaded WebAssembly build of FFmpeg — no special cross-origin isolation headers needed, just two small engine files served from this site (see the deployment README). Recording, the live preview, and WebM download always work regardless.