Engineering
Bleep and redact audio without uploading it anywhere
An AI model runs in your browser, transcribes your audio, and bleeps the words you pick. No server, no upload, no account. Your recording stays on your device.
6 min readRead more →
utility
Audio A/B Blind Test
Blind-test two audio files to hear the real difference. Free, private, runs in your browser.
How it works
01
Upload two audio files you want to compare (e.g., two mixes, two formats, before and after).
02
The tool matches their volume so loudness does not bias your comparison. In blind mode, files are labeled X and Y randomly.
03
Toggle between X and Y while listening. Click Reveal to see which was which.
No file uploadNo signupNo ads100% browser-based
Frequently asked questions
What is a blind A/B test?
A blind test hides which file is which so your judgment is based on sound quality alone. The tool randomly assigns your files to X and Y. You listen, pick your preference, then reveal the identity.
Why does the tool match volume?
Louder audio almost always sounds better to human ears, even when the quality is the same. Volume matching removes this bias so you can compare the actual sound quality.
Can I turn off blind mode?
Yes. Toggle blind mode off to see file names on the buttons instead of X and Y. Useful when you want a quick side-by-side comparison without the reveal step.
Does this upload my files to a server?
No. Both files stay on your device. All playback and volume matching happen in your browser.
Is this tool free?
Completely free. No account, no limits, no watermarks.
From the blog
All postsEngineering
How we built crash-safe recording with IndexedDB
Browsers crash. Tabs get killed. We write audio chunks to IndexedDB every few seconds so your recording survives no matter what.
4 min readRead more →
Product
16 free audio tools that run entirely in your browser
Trim, merge, EQ, compress, normalize, reverse, change speed, test your mic, and more. Every tool runs locally. No upload, no signup, no ads. Here is the full list.
7 min readRead more →
Need to record first?
Orec is a free browser-based recorder with crash-safe local storage and built-in editing.
Start Recording