Upload a reference audio file, then select a folder to search for similar files using spectral fingerprinting (Chromaprint-inspired, pure browser JS).
Choose a single audio file to use as reference.
Select a folder containing audio files to search through.
Upload one reference audio file, scan a folder, and Sakarto finds everything that sounds similar to it using spectral fingerprinting. The reference card is always pinned first — protected from move or delete — and matches appear after the scan completes.
Reverse Audio Search is the audio equivalent of reverse image search. Instead of scanning a folder and automatically grouping everything that sounds alike, you choose one specific audio file as your reference, then Sakarto scans a folder to find everything with a similar spectral fingerprint.
Use it when you already know what track you're looking for — for example: "find all copies and re-encoded versions of this specific song in my archive."
Upload a single audio file. Sakarto processes it immediately and displays a player so you can verify you picked the right file.
Select a folder and Sakarto fingerprints every audio file in it, then compares each against your reference using Hamming distance.
Audio processing continues even when you switch browser tabs. Unlike video scanning, the Web Audio API is never throttled in background.
The reference card is pinned first with a blue REFERENCE badge. It can never be accidentally moved or deleted.
Both the duplicate finder and this reverse search use the same pure-JavaScript Chromaprint-inspired fingerprinting pipeline. The difference is what gets compared to what: here, every folder file is compared against your reference only — not against each other.
When you select your reference audio, Sakarto processes it right away — before the folder scan starts. It decodes the file, resamples to 11,025 Hz via OfflineAudioContext, and computes its full spectral fingerprint. A preview player appears so you can confirm the file loaded correctly.
For each audio file in the folder, the browser decodes it at its native sample rate using AudioContext.decodeAudioData(), then resamples to 11,025 Hz mono. This normalizes MP3, WAV, FLAC, OGG, and M4A so they are all directly comparable regardless of original format.
The audio stream is split into overlapping 4,096-sample frames (hop size 1,024). Each frame is multiplied by a Hann window, then a pure-JavaScript Cooley-Tukey FFT converts it to a magnitude frequency spectrum covering 0–5,512 Hz.
The spectrum is divided into 16 equal bands. For each frame, 15 adjacent-band comparisons ("is band N louder than band N+1?") produce a 15-bit sub-fingerprint. This captures relative spectral shape — robust against loudness normalization, bitrate changes, and minor re-encoding.
After all folder files are fingerprinted, each is compared against the reference by XOR-ing their fingerprint arrays and counting differing bits (Hamming distance). If the bit-error percentage falls below the threshold set by the slider, the file is a match. A duration pre-check skips files shorter than 50% of the reference duration.
The reference card always appears at position 0 with a blue REFERENCE badge. All matching files are listed after it. Unlike the duplicate finder (which shows results live), reverse search completes the full scan first, then shows all matches together so you get a complete count before acting.
The Hamming Threshold slider (0–50) controls how strictly folder files must match your reference to appear in results. Adjusting it after a scan re-filters results instantly without re-scanning.
Only near-identical files match. Use for exact copies, same file at different bitrates, or lossless vs. lossy exports of the same master. Very few or no false positives.
Catches re-encoded versions, different bitrates (320k vs 128k), and light post-processing. A good starting point for music library searches.
Groups files with similar overall spectral character, even if content differs. Useful for finding recordings from the same session. Expect more false positives — always listen before deleting.
(slider²) / 50 — so slider 10 ≈ 2%, slider 20 ≈ 8%, slider 30 ≈ 18%. Fine-tuning at low values feels more impactful than at high values.Every audio card has a built-in player. Here's how to use it:
| Control | What it does |
|---|---|
| ▶️ Play button | Starts playback. Automatically pauses any other playing track on the page. |
| ⏸️ Pause button | Pauses playback. Audio position is remembered. |
| Progress bar | Click anywhere on the bar to seek to that position. Drag left/right to scrub. |
| 🔊 / 🔇 Mute button | Mutes or unmutes this individual track. |
| 🔇 Audio (toolbar) | Mutes or unmutes all audio on the page at once. |
| Time display | Shows current position / total duration (e.g. 1:23 / 3:45). |
| ← / → arrow keys | When the progress bar is focused, seeks backward or forward 5 seconds. |
Click Choose Reference Audio in the left panel. Select any audio file from your computer. Sakarto processes it immediately — a preview player with the purple art background appears so you can play the file and confirm you chose correctly.
Supported formats: MP3, WAV, FLAC, OGG, M4A, AAC. Files over 100 MB are not supported as reference files.
Once a reference file is loaded, Choose Folder to Search becomes active. Click it to open a native folder picker (Chrome / Edge). Or drag and drop a folder directly onto the page.
The folder count shows how many files were found. The Start Search button activates only when both a reference file and a folder are selected.
Click 🔍 Start Search. A progress bar shows how many files have been processed. Audio processing runs fully in the background — you can switch browser tabs freely without pausing the scan.
Once the scan completes, the reference card appears at position 0 (blue REFERENCE badge) followed by all matching files sorted by closeness to the reference. The result count shows how many similar files were found.
Use the Hamming Threshold slider above the results to tune sensitivity. Releasing the slider re-filters results instantly without re-scanning. Start at the default of 10 and raise it if you're missing expected matches.
Every card has a built-in player. Use it to listen and confirm similarity before taking action. Playing one track automatically pauses all others.
Ctrl+Click the reference card and one or more match cards, then click ⚖️ Compare. A modal opens with a player per file, full metadata (duration, size, type, path), and a similarity percentage. For 3+ files, a pairwise similarity matrix is shown.
The reference card in the compare modal shows only a Copy Name button — no Move or Delete — to keep it protected.
Select match cards (not the reference — it's protected) and use the toolbar. With Queue Mode on (recommended), files are staged first:
With Queue Mode enabled (default), clicking Move or Delete stages files in the Move Queue or Delete Queue tab. Switch to those tabs in the sidebar, listen to each file, remove any you change your mind about, then execute. The default destination folder is Audio-Duplicates, created inside your scanned folder.
| Button / Control | What it does |
|---|---|
| Choose Reference Audio | Select the audio file to search for. Player preview appears immediately. |
| Choose Folder to Search | Select the folder to scan. Activates once reference is loaded. |
| 🔍 Start Search | Begin scanning. Processes all folder files, then shows all matches. |
| Hamming Threshold slider | Adjusts matching strictness. Re-filters results on release without re-scanning. |
| 🔄 New Search | Reload the page and start fresh with a new reference file |
| 📋 Copy (N) | Copy selected filenames to clipboard. N = count. |
| 📂 Move (N) | Move match files or stage them in Move Queue (reference excluded) |
| 🗑️ Delete (N) | Delete match files or stage in Delete Queue (reference excluded) |
| ✕ Deselect All | Remove selection from all cards |
| ⚖️ Compare (N) | Open compare modal for Ctrl+clicked files. Needs 2+. |
| 🔇 Audio | Mute / unmute all audio players on the page |
| Queue Mode checkbox | Stage files for review before executing. Recommended on. |
| Click card | Select / deselect the card |
| Ctrl + Click card | Add / remove from compare list (purple border) |
| Click & drag (empty area) | Box-select multiple match cards |
| Right-click card | Context menu: Copy / Move / Delete / Compare. Move & Delete disabled on reference. |
| 🔍 hover icon | Open full-size preview with modal player. Reference shown as REFERENCE. |
| ▶️ on player | Play audio. Pauses all other players on page automatically. |
Always back up your audio library before deleting anything. Deleted files bypass the recycle bin and cannot be recovered.
Use the highest-quality, largest version of the file as your reference — a lossless FLAC or 320k MP3. A heavily compressed reference may produce fewer matches.
Begin with the default threshold of 10. If expected matches are missing, gradually raise the slider rather than jumping to a high value.
Use the built-in players to audition reference and match side-by-side before moving or deleting. The algorithm is good but not infallible for edge cases.
Use Move to an "Audio-Duplicates" folder rather than deleting immediately. Review the moved files over a few days before permanently removing them.
If Chromaprint finds nothing but copies clearly exist, try Essentia HPCP (better for harmonic similarity) or Meyda MFCC (better for timbral texture and spoken word).
Processing a typical 3–4 minute track takes 1–3 seconds on modern hardware. Large folders (1,000+ tracks) can take several minutes. Close other browser tabs to free up CPU.
The File System Access API bypasses the OS recycle bin entirely. Use Queue Mode to review files before executing any delete operation.
You can't scan two separate folders in one session. Workaround: scan their common parent directory so both are included.
Fingerprints for thousands of long tracks consume significant RAM. For libraries with 10,000+ files, scan in genre or artist subfolders.
The File System Access API is only available in Chrome 86+ and Edge 86+. Firefox and Safari can scan and display results but cannot move or delete files.
remove() method, which permanently deletes files and bypasses the OS Recycle Bin entirely. The reference file is protected and can never be deleted through Sakarto regardless. For everything else, always use Queue Mode: stage files in the Delete Queue, listen to each one using the built-in player, and compare them against the reference in the Compare modal before executing the deletion.