Chordly guide
Chordly is a free local preview for turning audio into an editable chord chart. It suggests chord changes, lets you listen and make corrections, and exports a chart for guitar or piano.
1. Choose a recording
Use a complete WAV or MP3 file you have permission to use. Audio stays on your device. Files must be 0.5 seconds to six minutes long, mono or stereo, and no larger than 50 MiB. WAV supports 16/24/32-bit PCM and 32-bit float at 8–96 kHz. Standard MPEG Layer III MP3 is supported; unusual tags, free-format MP3, AAC, FLAC and other containers are not.
Start with “Practice track” for an original, synthesized Am–F–C–G progression. It is a learning example, not a commercial recording or an accuracy benchmark.
2. Listen and review
Analysis runs in a browser worker. Cancel at any time to keep the previous chart. Select a passage in the timeline to seek playback. Choose a root, chord type and optional bass note, then press “Apply & review”, or mark a suggestion reviewed after checking it. Split a passage at the current playhead, at least 0.25 seconds from each edge. Merge keeps the selected chord across the next passage and resets its review status. Undo retains the last 30 edits in this session.
Use “Play from here” to start at the selected passage. “Loop selected passage” repeats its timing while you listen and play along; selecting or splitting a passage updates the loop. Playback speed ranges from 0.5× to 1.5× with the original pitch preserved in supported browsers. This changes playback only, not chart timestamps or chord pitch. Loops pause when the tab is hidden; resume with the play button. File replacement resets the practice controls. Browser scheduling may leave a small gap at the loop boundary.
3. Choose your instrument and key
Guitar shows a standard E–A–D–G–B–E voicing. Slash shapes include every chord tone and the specified lowest bass; when no compact shape is available, the editor says so and piano view remains available. A capo changes the displayed shape so it produces the chart’s sounding chord. Piano highlights the chord’s pitch classes across two octaves. Transpose changes the chart by up to 12 semitones in either direction; it does not alter the audio. Capo has no effect on piano view. A correction applies to the displayed chord and is converted back to the source pitch internally.
4. Export and save
Text contains timestamps and chord names. CSV includes displayed and sounding chords, capo, transpose and review status. JSON is a versioned editable chart backup with no audio. Legacy version 1 charts remain readable. Adding an extended chord or slash bass upgrades the chart to version 2; older Chordly versions cannot open that backup. “Save chart on this device” explicitly stores one chart in this browser profile; it does not sync to another device. Open a JSON backup, then choose the exact original audio file to reconnect playback without replacing your edits. Renaming the same file is fine; re-encoding it changes the match.
What suggestions can and cannot do
Recordings shorter than one analysis context (about ten seconds) use a spectral detector for major, minor, dominant seventh, minor seventh and half-diminished seventh chords. Longer recordings combine that detector with ChordNet, running locally in a browser worker. Confident contextual predictions can suggest all 13 chord types available in the editor: major/minor, dominant/major/minor seventh, suspended second/fourth, diminished/augmented, diminished/half-diminished seventh, and major/minor sixth. Slash bass requires your correction. Low-confidence contextual predictions retain the spectral result; confident silence or unsupported harmony may be marked unclear.
Before the first longer analysis, Chordly downloads about 32 MB of versioned tools from this website. Your browser may cache them for later visits. The download needs a connection; the recording and recognition stay on your device, with no model API calls. Cancel leaves your previous chart intact. If a download or analysis fails, retry after checking your connection or try a shorter recording.
These are draft suggestions, not verified transcriptions. Voice/piano and acoustic-guitar development recordings improved with the contextual method, but unsupported harmony also produced more false suggestions. Isolated rendered piano chords performed worse, so short clips retain the spectral method. These reused evaluations do not establish accuracy across genres, commercial mixes or all devices. Dense mixes, vocals, percussion, detuning, inversions and ambiguous sixth/seventh chords still need careful listening. Stereo is averaged for contextual analysis, with the stronger channel used if opposite polarity nearly cancels the sound; spectral evidence uses both channels separately.
The spectral method follows AudioLabs’ chroma/template approach. Contextual recognition uses ChordNet from ChordMini, a portable Musetric CQT and ONNX Runtime Web. See the recognition notices and runtime notices. Processing speed depends on the device; modern browsers with WebAssembly SIMD are required for longer recordings.
Review every passage
The progress bar shows which passages you have checked. Use Next unchecked to move through the remaining suggestions, or Next unclear to find passages with no selected chord. Review & next saves your decision and moves forward, wrapping to earlier unchecked passages. Review marks belong to you; they do not certify accuracy. Corrections and marks are included in JSON backups. Merge resets the resulting passage for another review, and Undo restores your last edit.
Print a rehearsal chart
Choose Print / PDF to open your browser’s print dialog. Select a printer or Save as PDF where supported. The chart includes every passage in order, its time, displayed chord and notes, review state, instrument, transposition and guitar capo. Unchecked charts are labeled drafts. Printing uses a white paper layout in either theme; your audio stays on your device. JSON Backup is the editable format.
Choose your appearance
Choose System, Light or Dark in the header. System follows your device setting. Your choice stays in this browser when storage is available and follows you between Chordly pages.
Preview availability
There is no song-title catalog, cloud library, product login or paid plan yet. No search ranking, universal song coverage or professional transcription accuracy is promised. Email/password and Google accounts, subscriptions and one-time purchases are planned for a later release after integration testing.