Ultra Fast Audio Converter & Editor

Every conversion on CriticShift is a real, complete audio format conversion—never just renaming the file extension (like changing .mp3 to .wav in the file name, which only breaks the file header). When you add a track, CriticShift decodes the actual sound data inside your file, applies your chosen quality, volume, and trim settings, and builds a brand-new, genuine audio file in your selected format so it opens and plays properly on any media player, phone, car stereo, or editing software.

Yes! CriticShift supports full two-way conversion across all 27 file extensions in the selector grid (ordered from most popular to specialized): MP3, WAV, M4A, FLAC, AAC, OGG, OPUS, WMA, AIFF, ALAC, AMR, AC3, M4B, M4R, WEBA, OGA, CAF, AIF, MP2, W64, AIFC, AU, SND, GSM, DSS, VOC, and AVR. Note that a few extensions in the list are sibling aliases of the same underlying format—such as AIFF and AIF (4-letter vs. 3-letter extension), AU and SND (Sun/NeXT audio), and M4A / M4B / M4R (MPEG-4 audio for music, audiobooks, and iPhone ringtones)—included so you can export the exact file extension your device or software expects.

No—once audio frequencies are discarded during lossy compression (such as when an MP3 or M4A is first created), that original recording data is permanently gone and cannot be recovered by format conversion (even AI audio enhancers only synthesize estimated highs rather than restoring the original sound). Still, converting a lossy file into an uncompressed format (like WAV or AIFF) or a lossless compressed format (like FLAC or ALAC) is very useful in two situations: when your hardware sampler, CDJ, or broadcast system strictly requires WAV/AIFF files, or when you trim and edit a track and want to save the result without putting it through a second round of lossy MP3 compression (known as generation loss).

Never. Unlike many online converters that upload your files to distant servers and limit how many minutes or files you can convert each day, CriticShift converts and edits your audio directly on your own device inside your web browser. Your personal songs, voice memos, and recordings stay completely private on your computer or phone, with no upload waiting times and no daily limits.

Yes! You can set custom start and end trim times or adjust volume (from 20% to 200%) inside Settings before converting, or open the built-in Player and click Trim Audio to drag the IN and OUT handles right on the sound wave. You can zoom in up to 32x to see tiny details, drag the sound wave left and right with your mouse or finger, and fine-tune your cut down to the millisecond.When you click Apply Trim, CriticShift cuts directly from the uncompressed audio in memory so your track is never degraded by double lossy compression.

• Uncompressed Audio (WAV, AIFF, AIF, W64, AU, SND, AVR): Stores the raw, untouched sound wave with no compression. Files are larger, making them ideal for studio editing, video production, and hardware samplers.
• Lossless Compressed Audio (FLAC, ALAC): Works like a ZIP archive for audio—shrinking file size by roughly 40% to 50% while keeping 100% bit-for-bit identical studio sound quality.
• Lossy Compressed Audio (MP3, AAC, M4A, M4B, M4R, OGG, OPUS, WEBA, WMA, AC3, MP2, AMR, GSM, DSS): Removes sound details the human ear is less likely to notice to make files 75% to 90% smaller for easy streaming, mobile storage, and voice recordings. (Standard .ogg files almost always use lossy Vorbis or Opus compression.)
• Multi-Codec Containers & Hybrid Formats (CAF, OGA, AIFC, VOC): Some extensions are flexible containers that can hold either uncompressed or compressed audio—for example, Apple's CAF can wrap uncompressed PCM, lossless ALAC, or lossy AAC; Xiph's OGA container can wrap lossless Ogg FLAC or lossy codecs; AIFC (AIFF-C) is Apple's compressed AIFF specification; and VOC supports both uncompressed PCM and compressed ADPCM voice data.

For everyday music and songs, 44,100 Hz (44.1 kHz) is the standard CD choice; for video editing, YouTube videos, and film, pick 48,000 Hz (48 kHz). When converting to lossy formats like MP3 or M4A, 320 kbps gives you the highest sound quality, 192 kbps offers a great balance between clear sound and smaller file size, and 64–128 kbps (or Mono) is great for voice recordings, lectures, and podcasts.

Keep in mind that Apple iOS enforces a strict 40-second maximum limit for iPhone ringtones (.m4r) and 30 seconds for text tones—any .m4r file longer than 40 seconds will not sync or appear in your iPhone's ringtone list. For the cleanest single-pass workflow, set your start and end trim times (under 30–40 seconds) inside Settings before clicking Convert so CriticShift trims the audio first and encodes directly to M4R. And if you prefer to trim visually on the waveform after converting, clicking Apply Trim slices directly from the uncompressed master audio held in browser memory so your ringtone is never re-compressed twice.

Yes. You can add as many audio files as you want at the same time—even if they are in different formats—and convert all of them together by clicking Convert All. Once finished, click Rename (or click the track title) on any card to type a new file name before clicking Save or Save All.

Yes. CriticShift works right in your web browser on Windows, Mac, Linux, iPhone, iPad, and Android phones and tablets without installing any apps. On phones and tablets, you can tap to pick audio files from your device and use your finger to zoom, scroll, and drag the trim handles on the sound wave.