Converts AAC files to MP3 format — modern streaming services, YouTube, and devices where AAC is the native codec to universal music playback and sharing across all devices and platforms. All conversion happens locally in your browser with no file size limits.
Runs on FFmpeg
Content reviewed October 2026 · About Toolzum
Convert legacy WMA to efficient AAC for modern players and phones. Rescue Windows Media libraries for today — 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 MKV to legacy AVI for old players and embedded systems. Reach hardware that accepts nothing newer — local FFmpeg work, unlimited saves.
Stamp text watermarks across PDF pages — DRAFT, CONFIDENTIAL, custom text with opacity. Protect 50 filings before sharing — local pdf-lib 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. MP3 (MPEG-1 Audio Layer 3) uses lossy compressed encoding and excels at universal music playback and sharing across all devices and platforms. 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.
Car stereos, cheap players, and legacy software play MP3 exclusively. Leaving Apple's ecosystem demands the universal format.
192 kbps minimum for music transcoded from AAC; 128k suffices for podcasts. Lossy-to-lossy always costs a generation — pay bitrate to hide it.
Protected store files can't convert — only DRM-free copies you own. Subscription downloads stay locked by design.
No — conversion runs locally in your browser with FFmpeg. Saves never touch a meter — downloads on local tools 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.