ShadowTag

Built for sound designers, sample library owners, and post-production teams who need complete, accurate metadata across large collections of audio files.

ShadowTag is a first class modern macOS application. Designed for macOS 26, all tools are multi-threaded and run as fast as possible — scaling across every available core. Process a handful of files or an entire library — the work happens in parallel. ShadowTag is fast.

ShadowTag reads and writes every major metadata standard — ID3v2, Vorbis Comments, MP4 atoms, BEXT, iXML, XMP, and UCS — directly into your audio files, keeping your library portable and compatible with any DAW, asset management system, or licensing platform.

Everything is non-destructive to audio. ShadowTag only modifies metadata.

Library Management

Organize files into playlists and playlist groups. ShadowTag stores references, not copies — your files stay where they are. Playlists persist automatically as you work and are fully restored on next launch. Drag files or entire folders from Finder to add them; folders are scanned recursively for supported audio formats.

Finder Tags & Custom Colors

ShadowTag reads and writes macOS Finder Tags, so the colored labels you assign in the app are immediately visible in Finder and Spotlight. Beyond macOS's built-in palette, ShadowTag lets you define custom tag colors, giving you a broader visual vocabulary for marking file status, review state, or any workflow distinction your library needs.

Metadata Editing

A unified Editor panel exposes all metadata standards in one place. Select multiple files to view and edit shared values across a whole selection at once. Unsaved changes are tracked per file and shown inline in the file list.

Supported standards and file types:

Automated Analysis

Let ShadowTag tag your files for you. All analysis runs entirely on-device — no internet connection required — and results are written directly into the file's metadata.

• Loudness — Full EBU R128 analysis: integrated loudness, loudness range, true peak, max momentary, and max short-term. Results go to ID3 tags and, for WAV files, the BEXT loudness fields.
• Tempo — BPM detection written to the BPM metadata field. Also drives the built-in metronome during playback.
• Musical Key — Pitch class and tonality detection, written to the ID3 Initial Key field.
• Detect Keywords — On-device sound classification generates descriptive keywords for quick searching and filtering.
• UCS Category — Automatic UCS category and subcategory suggestions based on filename, existing tags, and audio content analysis.

UCS Support

ShadowTag has first-class support for the Universal Category System — the open standard for categorizing sound effects used by professional sound libraries and sync licensing platforms worldwide. Edit all standard fields directly: Category, Subcategory, and Category ID. UCS data are stored as ID3 TXXX tags so are visible in any other application.

Use Tools > Detect UCS Category to auto-suggest categories, and Tools > Rename to UCS Convention to rename files to the UCS filename standard.

Playback & Auditioning

A built-in audio player lets you audition files in context. The waveform view shows playback position in real time with support for loop regions, playlist mode (auto-advance), and markers. Load Audio Unit plug-ins into the signal chain to audition files through your processing — without modifying the file. ShadowTag can also play video files and display their embedded metadata such as XMP.

Markers are stored in the appropriate format for each file type: cue points in WAV, marker chunks in AIFF, ID3 chapters in MP3, chapter atoms in M4A/MP4, and Xiph chapter tags in FLAC and OGG.

Audio Format Conversion

Convert files to any supported format from within your library. Output formats: WAV, AIFF, MP3, FLAC, OGG Opus, CAF, M4A. Options include sample rate, bit depth, channel count, MP3 bit rate, metadata handling, and file conflict behavior. Converted files can be added to a new playlist automatically.

ADD Audio Import

ShadowTag can convert (.addAudio) files from Audio Design Desk, translating ADD's proprietary metadata into standard tags. Files are losslessly converted to WAV or M4A during import, and ADD specific fields — category, subcategory, descriptors, tempo, key, and more — are mapped to their ID3/INFO standardized equivalents, enabling your older ADD sounds to be externally accessible and searchable alongside the rest of your collection. ShadowTag is the only application that can convert these files.

Search

Full-text search across all playlists or within the current playlist. Search queries match against all indexed metadata fields. Results appear in a dedicated Search Results playlist and can be dragged into any other playlist to keep.