無料オンライン音声トリマー（高精度MP3・音声カット）

オンラインで音声を高精度にトリミングする手順

Trimming an audio recording is one of the most fundamental tasks in digital sound editing. Whether you need to remove an awkward pause at the start of a podcast interview, extract a specific speech snippet for a social media video reel, or create a custom mobile ringtone from a song, having a reliable online audio trimmer makes the process effortless.

Traditional audio workstations such as Audacity, Adobe Audition, or Reaper require software installations, complex timeline setups, and steep learning curves. Our online audio trimmer runs completely inside your web browser. Using the native HTML5 Web Audio API, it decodes raw PCM audio data directly into your browser's memory, giving you instant timeline scrubbing, dual draggable boundary handles, and zero server upload latency.

操作手順ガイド：

1. Select Your Audio File: Drag and drop your audio file into the box above, or click to choose an MP3, WAV, M4A, AAC, FLAC, or OGG file from your computer or phone. Files up to 150 MB are supported.
2. Position the Boundary Handles: Use the left purple handle to establish your start timestamp and the right purple handle to choose your end cut point. You can drag the handles directly or fine-tune with the +/- 0.1s millisecond stepper buttons.
3. Preview Your Selection: Click 選択範囲を再生 to listen specifically to the audio between your start and end markers. Toggle Loop to continuously rehearse the exact transition point.
4. Choose Trimming Mode & Fades: Keep the default Keep Selection mode to save only the highlighted audio, or switch to Remove Selection to cut out a section from the middle of the track. Optionally enable artistic 1-second Fade In and Fade Out curves.
5. Download Your Processed Audio: Click Trim Audio Now. In milliseconds, your audio is sliced, smoothed with anti-click micro-fades, and encoded into both 192 kbps MP3 and Lossless WAV format ready for instant download.

クリックノイズ防止技術：低品質カッターの雑音を防ぐ仕組み

Have you ever trimmed an audio file with a basic online tool only to hear an annoying sharp "pop" or "click" at the exact moment the track starts or ends? That audible artifact is caused by DC offset and non-zero-crossing waveform truncation.

Audio waveforms oscillate between positive and negative values thousands of times per second. If you abruptly slice a digital audio file while the sound wave is near its peak or trough (for example, at an amplitude of +0.8 or -0.7), the audio hardware's speaker diaphragm is forced to jump instantly back to zero voltage. This instantaneous step voltage creates an unpleasant speaker pop.

Our audio trimmer engine solves this problem permanently. Every cut is treated with a 5-millisecond raised-cosine micro-fade (Hann curve) applied directly across boundary samples. This smoothly ramps the voltage from zero to full amplitude at the start, and from full amplitude back down to absolute zero at the finish. The result is a clean, broadcast-ready splice with zero clicks, zero pops, and zero distortion.

保存形式の選択：192kbps MP3と無劣化スタジオWAVの違い

When your audio is trimmed, you are provided with two immediate download options. Both are generated in-memory simultaneously so you never have to wait for secondary encoding.

For most everyday voice recordings, podcast episodes, and social media videos, the 192 kbps MP3 format delivers exceptional perceived acoustic fidelity while occupying nearly 90% less storage space than uncompressed WAV files. However, if you plan to import your trimmed audio into a digital audio workstation (DAW) for further mastering or multi-track mixing, downloading the lossless WAV ensures that no lossy re-encoding artifacts are introduced into your production pipeline.

音声トリミングの活用シーン

• Podcast Editing: Quickly cut out banter, coughing, microphone tests, or awkward silence before the intro music starts. Combine this with our AI Remove Silence tool to produce tight, professional podcast episodes.
• Voiceover Post-Production: Isolate the best take from a long voiceover recording session. Cut out warm-ups, false starts, and page turns in seconds.
• Custom Mobile Ringtones: Trim a catchy 20-second chorus or hook from your favorite audio track, add smooth fade-ins and fade-outs, and export directly as an MP3 ringtone.
• Social Media Soundbites: Extract 15-second or 30-second audio clips from keynote speeches, webinars, or interviews to accompany Instagram Reels, TikTok videos, or YouTube Shorts.

よくある質問（FAQ） (FAQs)