How to use it

ChordStamp reads a tab file and writes the harmony back into it: chord names and fingering diagrams over every bar, plus a few things your tab software won't do for you. Around that sits a library for your own collection and a learning hub that hands you practice files. Everything below is free to try; nothing needs an account.

Stamping a file What every option does Pasting a tab Your library Learn & practice files Tuner Free tier & licence If something goes wrong

1 · Stamping a file

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Open Stamp and drop a file in. Accepted: .gp3, .gp4, .gp5 (classic tab files), .gpx and .gp (newer ones), and MusicXML (.musicxml/.mxl) exported by notation software. Up to 10 MB.

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Pick your options, listed in the table below. The defaults (backing track, humanize, polish) are the ones most people want.

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Press Stamp, then Preview if you want to see and hear it in the browser first. The download is always a .gp5, which every tab app opens.

Your file is processed and deleted the instant the download starts. Nothing is stored, ever. Keep your originals; we suggest never overwriting one with an output. See the Privacy Policy.

What you get back

Chord names and diagrams above every bar, on every track, voiced near where that track actually plays: open shapes down at the nut, barre and 7th grips up the neck.
Mid-bar changes get their own stamp when the harmony really moves inside the bar, instead of being smeared into one label.
The key, written into the file's subtitle so it travels with the file.
Your own chords are never touched. If the transcriber already wrote chord names, those stay exactly as they are; we only fill the gaps, and add fingering diagrams to name-only chords.

2 · What every option does

Option	What it does	Use it when
Backing track	Adds a strummed rhythm track on its own mixer channel, following the detected chords in any time signature. Ships muted.	You want to jam over the song. Unmute it in your tab app's mixer.
Strum pattern	Gives that backing track a real rhythm instead of block chords: folk (D‑DU‑UDU), eighths, ballad, country, rock, or your own D/U/– pattern.	The block-chord backing feels stiff.
Humanize	Velocity shaping: downbeat accents, softer offbeats, a little deterministic jitter.	Playback sounds robotic. Safe to leave on.
Polish	Fixes lazy authoring defaults only where the author left them: everything panned centre, missing let-ring on arpeggios, MIDI channel collisions, bone-dry reverb.	Almost always. It never overrides a deliberate choice.
Changes only	Stamps a chord just when the harmony changes rather than on every bar.	You find a label on every bar noisy.
Confidence notes	Writes each chord's confidence as small text, so 84%, or ?68% for bars worth a second look.	You're checking the analysis rather than just playing it.
Section markers	Adds rehearsal markers (A, B, C…) at the start of each lyric block.	You're navigating a long song.
Lyrics	Paste lyrics and they land in the file's own lyric lane, lined up with the bars. Blank lines separate sections; `@17` on its own line anchors the next block at bar 17; hyphens split syllables.	The tab has no words in it.

3 · Pasting a tab instead of uploading

On the Stamp page, switch to Paste a tab. Two kinds of text work:

ASCII tab: the classic six lines of dashes and fret numbers. Hammer-ons, slides, bends, palm mutes and dead notes come through, and chord names written above the tab are kept as the chart's chords.
A chord sheet: chords over lyrics, no tab lines at all. [Section] headers become markers, every chord gets a playable grip, and the lyrics land in the lyric lane under them.

Set the time signature and the strum rate before converting; text tab carries no rhythm, so we place notes on a sixteenth grid scaled to each bar. Expect to nudge a few durations afterwards; the notes, chords and key will be right.

4 · Your library

Library points at the folder of tab files you already have and makes it usable. It all happens in your browser. The folder is read locally, and the only file that ever reaches our server is one you explicitly press Stamp on.

Open your folder once. Tens of thousands of files index in seconds. In Chrome or Edge the folder is remembered between visits; in other browsers you re-pick it each time.
Search as you type, jump by letter, or browse by artist. Album art is fetched per artist by your own browser.
key? on any row detects that song's key and progression. Click the result to open Learn in that key, and scales, CAGED map and jam sheet all follow.
▶ previews the notation with playback, so you don't open five files to find the right one.
Stamp per song, or batch a whole artist or your starred list (licensed). Outputs can download normally or save into a ChordStamp/ folder beside your originals.
★ and ✓ tabs hold your favourites and everything you've stamped, including generated practice files.
Settings → Backup exports your practice files, detected keys and settings as a .zip you keep.

No folder handy? Drag a single tab file onto the page and it stamps just that one.

5 · Learn, and the practice files

Learn is a free interactive hub: fretboard and scale maps, the CAGED system, an interactive circle of fifths, chord identifier, ear training, metronome, and a weekly practice plan. Everything follows one key, so changing it anywhere changes it everywhere.

The part worth knowing about: most tools there can hand you a real tab file. Look for the small ♪ Practice file buttons. They generate a drill (CAGED positions, a scale in three positions, a chord loop, the spider warm-up, the barre ladder, a 12-bar blues, or an alternating-bass fingerstyle pattern) and drop it on your library's practice shelf, where you can preview it, export it, or open it in your tab app. The theory page and your practice folder are the same place.

These drills are generated exercises, not songs, so they're yours to keep and share freely.

6 · Tuner

Tuner is a chromatic tuner using your microphone. Your browser will ask permission the first time; the audio never leaves your machine. Learn's Strings & Tuning section also plays reference notes if you'd rather tune by ear first.

7 · Free tier and the licence

Free: a few files a month, with every feature included, nothing crippled. The library, Learn, practice files, preview and the tuner are always free and unlimited, because they run in your browser.
Lifetime licence: one payment removes the monthly limit and unlocks batch stamping and the full analysis output.
No accounts. You get a key, saved automatically in the browser you bought it in. Copy it into a password manager; that's your proof of purchase. Lost it? Email us from the address you paid with.
Using another device? Paste the key into the account chip in the top bar.

See the Terms for what "lifetime" means in writing, and the refund policy.

8 · If something goes wrong

What you see	What's happening
"Not a readable tab file"	The file is corrupt, often an error page that got saved with a .gp3 name. Open it in your tab app to check.
Chords look wrong in places	Detection reads what's actually played, and a bar can genuinely be ambiguous. Turn on Confidence notes to see which bars it was unsure about. It stays silent rather than guess when evidence is thin.
No chords on some bars	Those bars didn't carry enough harmony to name honestly: single notes, drums, or silence.
The backing track is silent	It ships muted on purpose. Unmute it in your tab app's mixer.
Library forgot my folder	Folder memory needs Chrome or Edge (and Brave with the File System Access API enabled in brave://flags). Other browsers re-pick per visit; everything else still works.
"Free tier is N files/month"	You've used the month's free stamps. The browser-side tools keep working, or grab a licence.

Anything else, or anything that just feels wrong, goes through the feedback button in the top bar. It goes straight to the maker, no account, and the page you were on comes along so we know where to look.