01Zero upload
Open media locally
Drag and drop your audio or video file. The browser demuxes the media container and prepares Web Audio DSP filters in memory without transmitting any data over the network.
Free Online Audio Editor · 100% Browser-Local
Keep the pause.Cut the dead air.
A free silence remover and complete end-to-end audio pipeline — 100% private in your browser.
Natural Pause & Dialogue Review Studio
Ready for a local audio or video file
Local Browser Audio Engine
Scanning speech & quiet pauses…
Reading media and computing RMS energy…
1Reading file
2Decoding audio
3Scanning quiet
4Building map
Loudness:-16.0 LUFS
Peak:-1.0 dBFS
0:00 savedPacing Preset
Speech cushionsFine-tune detection parameters
Balanced
Balanced (~-38dB): Calibrated natural balance recommended for podcasts, YouTube videos, and dialogue.
0.80s
0.20s (all micro-pauses)2.50s (only long pauses)
0.32s
0.00s (flush / jump)0.80s (spacious)
Automatically removes silence before first speech and after last speech.
Pause #01✂️ Cut Proposed
00:14.2 → 00:16.8 (2.6s gap)
1.6s quiet gap; keeps 0.32s breathing room.
Tip: Press Del or Backspace to cut selected silenceR to keep
Silence Map (0)
0 silences found (0.0s dead air) · 0 will be cut, 0 kept
Target ScopeAll Clips
All edits reversible
Studio DSP & Ambience Rack
Real-Time DSP✨
1-Click Full Background Noise Removal
Removes 80Hz rumble, 50/60Hz hum, room hiss & mouth clicks
Anti-Blackout
Fills shortened silence gaps with authentic room tone synthesized from your recording, eliminating unnatural "vacuum dropouts".
Butterworth
-40 dBFS
+2.5dB Clarity
Sibilance
Cubic Spline
-1.0 dBFS
Subtitle Range Protection
Protect Intentional Sentences & Pauses
Importing your subtitle transcript locks dialogue boundaries so dramatic reflections and deliberate speech pauses inside sentences are never auto-cut.
No subtitles loaded
Hesitation Splicer (Fillers & Stutters)
Removes verbal hesitation sounds (um, uh, er, like) and repeated stutters.
0 fillers0 stutters
Merged with acoustic cuts
A/V Dual-System Sync
Drift ConformerEdit Evidence & Provenance
Manifest v1.0Total Proposals
0
Active Cuts
0
Restored Pauses
0
Protected Lines
0
Structural Export Validation:
✔ Zero server uploads (100% Client-Side)
✔ True-Peak Limiter ceiling ≤ -1.0 dBFS
✔ Duration conservation verified (Δ ≤ 5ms)
✔ 8ms anti-click zero-crossing micro-fades
Media Preflight & Capabilities
Source Format:Audio Track
Sample Rate:44.1 kHz
Channels:Stereo (2-ch)
Memory Footprint:~12 MB RAM
Local Processing:100% Client-Side
Verified Export Options:
- ✔ 16-Bit PCM WAV: Uncompressed lossless master audio.
- ✔ Audacity Labels: Drag-and-drop label track for Audacity / Reaper.
- ✔ CSV Cue Sheet: Tabular marker list with exact timestamps.
- ✔ EDL / FCPXML: Timeline cut lists: EDL for Premiere & Resolve, FCPXML for Final Cut & Resolve.
- ✔ Evidence Manifest: JSON & CSV audit trail with a CRC-32 source checksum.
Episode Show Notes
Silence #01 detected (00:04.4 → 00:05.0)
🎬Sequence Track1 clip
Pause Map & Timeline
Click / drag to scrub0:000:00
✨
✨ Cleaning Noise...Background Noise Remover
Multi-band spectral Wiener filtering & room rumble removal
Strong (75%)
0% (Off)50% (Balanced)100% (Studio Max)
Space Play/Pause · Del Trim · R Keep · J/L Jump 2sDouble-click waveform to trim
Lossless 16-Bit Master Audio & Edit Ledger Export
Rendered locally in browser memory with 8ms anti-click micro-fades. Zero server upload.
Detected from video
Chain in Studio FlowTimeline files reference your media by file name only. Final Cut Pro, DaVinci Resolve or Premiere Pro will ask you to relink the clip to the original file.
✨ Hover any tool icon to see what it does · Click to launch
100% Private Web Audio: Your files never leave your device. Zero cloud limits, zero subscriptions.
Workflow Architecture
Three steps to clean speech & natural pacing
How to remove background noise from video and audio recordings with reviewable, non-destructive editing.
02Reversible
Review cuts & noise cleanup
Inspect detected dead air on the interactive waveform and audition audio noise reduction. Switch between Natural, Tight, and Fast presets or restore specific dialogue pauses with one click.
03Lossless audio
Export clean media
Download your finished master audio as uncompressed 16-bit PCM WAV with 8ms anti-click crossfades, or export synchronized NLE edit decision lists (EDL/FCPXML) for video editing.
Acoustic Engineering & Precision DSP
Engineered for human speech rhythm
Why podcasters, video editors, and voice creators choose reviewable pacing and client-side intelligence over aggressive cloud noise gates.
Retained Speech Cushion
Natural mode preserves a 0.32s ambient pause around words, preventing clipped consonants and unnatural breathless delivery.
Dual-Pass Noise Cleaner
Filters 80Hz HVAC rumble, removes 50/60Hz electrical hum, attenuates room hiss, and reconstructs mouth clicks using Hermite splines.
True-Peak Headroom Limiter
Hard -1.0 dBFS true-peak ceiling protects audio from inter-sample clipping and distortion across mobile speaker drivers.
Zero-Server Privacy
100% of processing runs locally via browser Web Audio. Zero uploads, zero telemetry, and complete NDA compliance.
Supported Capabilities · Free Online Audio Editor
Comprehensive audio cleanup & speech finishing tasks
From cleaning microphone rumble to synchronizing subtitles, perform essential spoken-word audio and video workflows directly in your browser.
Video & Audio
Remove Noise from Video & Audio
Perform audio noise reduction online to remove background noise from video recordings and voice memos without cloud uploads.
0.32s Cushion
Remove Silence & Dead Air
Shorten awkward pauses and remove silence from video online while keeping natural conversational breathing rhythms intact.
+18 dB Gain
Make Audio Louder Online
Boost low-level voice recordings up to +18 dB with soft-knee compression and True-Peak limiting to prevent digital distortion.
Speech & Text
Convert PDF to Audio & Speech
Convert PDF documents and articles into natural speech audio, or transcribe audio to text online with synchronized subtitle markers.
Acoustic Engineering Guide · Speech Pacing
What is Auto Silence Cut? The Science of Speech Pacing
AutoSilenceCut is a free online audio editor engineered to detect and cut silence in voiceovers, podcasts, and video dialogue while preserving natural conversational rhythm and acoustic room tone.
25ms Windows
RMS Silence Detection
Continuous 25ms sliding-window energy analysis scans dialogue to isolate quiet pauses between words and sentences without false triggers.
0.32s Cushion
Speech Cushioning
Preserves calibrated ambient padding around words, protecting phonetic decay and natural inhale beats from breathless cutting.
8ms Micro-Fade
Anti-Click Crossfades
Applies equal-power cosine crossfades across boundary zero-crossings, preventing DC offset clicks and audible pops when audio is spliced.
Zero-Upload
Private Web Audio
Runs 100% inside your client browser. Media files, waveforms, and filenames never touch cloud servers, ensuring total project privacy.
16-Bit PCM WAV
Lossless Master Export
Direct rendering via OfflineAudioContext exports uncompressed 16-bit PCM RIFF WAV masters, avoiding lossy MP3 re-encoding artifacts.
Reversible DAW
NLE & DAW Integration
Audition individual cuts with 'Hear Before' previews, restore pauses with hotkey R, and export CMX 3600 EDLs or Audacity label tracks.
Dedicated Workflows
Specialized silence trimming for your workflow
Explore purpose-built workflows optimized for specific recording mediums.
Audio Silence Remover
Voiceovers, audiobooks, and uncompressed 16-bit WAV mastering.
Video Silence Remover
YouTube videos, presentations, and synchronized video preview.
Dead Air Remover
Lectures, webinars, and long silent gaps in raw recordings.
Podcast Silence Cutter
Multi-host shows, natural pacing, and -16 LUFS loudness target.
In-Depth Engineering Guide
Browser-Local Dialogue Finishing: How AutoSilenceCut Works
Acoustic Silence Removal with Natural Breathing Cushions
Traditional noise gates and basic silence cutters often ruin speech pacing by chopping off word endings and muting natural breathing pauses. When every quiet space gets deleted, spoken dialogue ends up sounding hurried, breathless, and artificial. AutoSilenceCut approaches speech pacing differently. Operating as a silence remover from audio and video recordings, the engine divides incoming waveforms into 25-millisecond analysis windows to measure root-mean-square (RMS) energy against a dynamic decibel floor. Instead of cutting right to the edge of spoken words, the detector applies a calibrated 0.32-second acoustic speech cushion to both sides of each pause. This cushion retains the natural decay of consonants, gentle room reflections, and conversational inhale beats. Boundary micro-fades of 8 milliseconds prevent digital clicks at splice points. You can preview every proposed cut on an interactive HiDPI waveform, toggle individual pauses back on, and audition edited passages before exporting. The result is tightened dialogue that sounds human, coherent, and comfortable to listen to.
Dual-Pass Background Noise Removal and Vocal Restoration
Spoken audio recorded outside treated broadcast booths frequently suffers from air conditioning hum, electrical ground buzz, and room reverberation. AutoSilenceCut includes a background noise remover that runs directly in your browser. The first pass applies an 80Hz second-order Butterworth high-pass filter to strip HVAC rumble, followed by narrow notch filters at 50Hz and 60Hz to eliminate mains hum without dulling fundamental voice frequencies. A downward expander then attenuates room ambience during quiet intervals. To remove background noise from video files, the tool demuxes MP4 and MOV streams in local memory before audio filtering. For transient disturbances like saliva mouth clicks, a moving variance detector identifies energy spikes and reconstructs the waveform using four-point Hermite cubic splines. If you need to boost low-level recordings, the integrated voice enhancer applies presence equalization and soft-knee limiting without distortion.
Text-Based Video Editing, Speed Control, and Speech Synthesis
Beyond acoustic filtering, the workspace provides text-guided timeline tools to edit video online free from clutter. Client-side speech recognition transcribes audio into word tokens with millisecond timestamps, letting you transcribe audio to text free and export synchronized SRT or WebVTT captions. The engine detects repetitive false starts, stumbling takes, and verbal hesitations to remove filler words from video timelines while keeping the surrounding sentences intact. When working with multi-camera setups, the system can sync audio video tracks by calculating normalized cross-correlation across syllabic energy envelopes to align external microphone recordings with camera scratch audio. An in-browser text to voice generator converts written scripts into spoken sound using speech synthesis with adjustable rate and pitch. You can also change playback tempo with a video speed changer, trigger effects with a custom soundboard online, or reverse audio online for creative sound design.
Broadcast Loudness Standards, Timeline Export, and Client Privacy
Finishing voice tracks requires meeting recognized loudness benchmarks before release. The built-in audio normalizer analyzes integrated loudness under ITU-R BS.1770 and EBU R128 specifications, targeting -16 LUFS for stereo podcasts and -14 LUFS for web video dialogue. A brickwall true-peak limiter holds inter-sample peaks at -1.0 dBFS to prevent clipping when files are compressed for distribution. Because creators handle multiple media formats—such as preparing speech extracts or turning video to MP3—all processing happens entirely inside your browser using the HTML5 Web Audio API and WebAssembly. No audio clips, video frames, or transcripts are sent to remote servers or cloud databases. You can audition your recording in three distinct playback modes: edited audio, raw original audio, or diff mode, which isolates only the excised gaps so you can verify no spoken consonants were clipped. Timeline markers can be exported to CMX 3600 EDL, Final Cut Pro XML, Audacity label tracks, or RFC-compliant CSV ledgers for external DAWs. When rendering is complete, your finished master exports directly to uncompressed 16-bit PCM RIFF WAV format, giving you clean, broadcast-ready dialogue with complete privacy.
Acoustic Standards & Research
Editorial Learning Centre & Engineering Guides
Deep-dive technical guides on speech acoustics, ITU-R BS.1770 loudness, pause pacing, and noise cleanup.
Topic 02Silence & Pacing
Why Silence Removal Sounds Choppy & How to Fix It
Learn the acoustic anatomy of speech pauses, syllable decay envelopes, and how 0.32s cushions protect conversational rhythm.
Topic 01Noise & Clarity
Remove Background Noise from Audio & Video
Downsampling 80Hz HVAC sub-rumble, stripping 50/60Hz mains hum, and repairing saliva mouth clicks with Hermite splines.
Topic 04Podcast Loudness
Audio Normalization vs Compression for Spoken Word
Achieving -16 LUFS (stereo) and -19 LUFS (mono) broadcast loudness standards without pumping or digital clipping.
Knowledge & Architecture
Frequently asked questions
Everything you need to know about browser-local noise removal, silence trimming, and natural speech pacing.
Can I remove background noise from video directly in my browser?+
Yes. AutoSilenceCut demuxes the audio stream directly from MP4, MOV, and WebM video files locally in browser memory. It processes the signal through Web Audio Biquad DSP filters—filtering low-frequency HVAC rumble below 80Hz, electrical mains hum at 50Hz/60Hz, and stationary room hiss via downward expansion—without uploading video bytes to any server.
How do I remove background noise from video and audio recordings?+
To remove background noise from video or audio, drag and drop your recording into the workspace. The engine automatically scans background quiet intervals to profile stationary room noise, activates high-pass rumble filtering, and suppresses room hiss during pauses while preserving natural vocal frequencies. You can audition the enhanced output in real time before exporting.
Why does AutoSilenceCut shorten silence instead of deleting all pauses?+
Completely stripping all quiet intervals makes speech sound unnatural, hurried, and breathless. AutoSilenceCut preserves a calibrated 0.32-second breathing cushion around spoken words in its default Natural mode, protecting phonetic decay and inhale beats so dialogue sounds conversational rather than robotic.
How does 100% browser-local processing protect my recording privacy?+
All audio decoding, waveform rendering, noise filtering, silence cutting, and WAV encoding execute strictly on your device using the HTML5 Web Audio API and OfflineAudioContext. Your media files, transcripts, and filenames are never transmitted to cloud servers, preventing data leaks on confidential interviews and client recordings.
Can I transcribe audio to text or convert PDF documents to audio?+
Yes. AutoSilenceCut includes dedicated tools to transcribe audio to text and sync subtitle cues (SRT/VTT), as well as speech synthesis utilities to convert PDF documents, articles, and images into clean, spoken audio locally in your browser.
How can I make quiet audio louder without causing digital clipping?+
AutoSilenceCut uses clean linear and soft-knee gain amplification up to +18 dB paired with a brickwall True-Peak limiter set to -1.0 dBFS. This amplifies quiet voices and balances dynamic range without introducing harsh square-wave clipping or distortion.