Converts AAC files to Opus format — modern streaming services, YouTube, and devices where AAC is the native codec to voice-over-IP, real-time communication, and streaming at very low bitrates with excellent quality. All conversion happens locally in your browser with no file size limits.
Runs on FFmpeg
Content reviewed October 2026 · About Toolzum
Convert AIFF masters to efficient AAC for sharing and streaming previews. Send listenable links without huge uploads — local FFmpeg work, unlimited saves.
Convert MP3 to AAC for better quality per bit on Apple devices and streaming. Modernize libraries for smaller sizes — local FFmpeg work, unlimited saves.
Convert OGG Vorbis to AAC for Apple and streaming compatibility. Move open audio into mainstream players — local FFmpeg work, unlimited saves.
Convert Windows ICO icons to ultra-efficient AVIF for modern web use. Shrink favicon libraries for the fast web — local Canvas work, unlimited saves.
Shrink JPG, PNG, and WebP photos with an Image Quality slider (10–100%, default 80%) plus a Resolution Scale slider, shown in Before/After panels with exact KB and -% savings. Single-image uploads up to 50MB — local library work, unlimited saves.
AAC (Advanced Audio Coding) uses lossy compressed encoding and is best for modern streaming services, YouTube, and devices where AAC is the native codec. Opus (Opus Interactive Audio Codec) uses lossy compressed encoding and excels at voice-over-IP, real-time communication, and streaming at very low bitrates with excellent quality. Converting between them lets you take advantage of each format's strengths — for example, using a compressed format for sharing and a lossless format for editing. All conversion happens locally in your browser with no file size limits.
24–32 kbps Opus delivers clear voice — a 60-minute show shrinks near 15 MB. Music needs 64+ kbps to avoid artifacts.
Opus is their native codec — converting upfront skips server transcoding and sounds better than MP3 at these rates.
One lossy generation; voice survives transparently, music suffers audibly. Keep AAC/FLAC masters for music.
No — conversion runs locally in your browser with FFmpeg. Only saves touch the network — downloads are unlimited.
Text to Speech (TTS)
Generate natural-sounding speech from text using your browser's built-in voices. Adjust speed and pitch — download your text as .txt.
Audio Cutter
Trim and cut audio files online — MP3, WAV, M4A, FLAC, and OGG. Set start and end times with sliders, then download the trimmed MP3 clip.
MP3 to WAV
Converts MP3 files to WAV format — universal music playback and sharing across all devices and platforms to professional audio editing, mastering, and archival in DAWs and production software. All conversion happens locally in your browser; files up to 100 MB each.
Speech to Text
Dictate live microphone speech to text in multiple languages through your browser's speech service. Live captions for meetings and notes — free to start, no Toolzum account needed.
MP3 Compressor
Shrink MP3 files by lowering bitrate with quality presets — fit podcasts into feed limits. Cut a 50 MB episode to 15 MB cleanly — local FFmpeg work, unlimited saves.
Apple Music Preview Extractor
Extracts publicly available 30-second audio preview clips from Apple Music by resolving the store URL. Free to start with no signup.