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Free ISWC tool

ISWC lookup,
made simple

Have a recording and want the song behind it? Have an ISWC and want every version ever recorded? Use the tool below. Free, no sign-up, no jargon.

By Christiaan Maks, Founder & DeveloperUpdated

Find a recording's ISWC

Paste an ISRC (or a SonoVault track ID) to see the composition code(s) behind that recording.

Find recordings of a work

Enter an ISWC to list every recording of that composition: originals, covers, remixes, and re-releases.

Free, no sign-up. Searches a catalog of 90M+ recordings. ISWCs are sourced from The MLC, and no aggregated source is complete, so not every recording is mapped to a work. Results are for reference; verify against an authoritative source before any filing, licensing, or financial use. SonoVault is not affiliated with The MLC or any collecting society.

Works, not recordings

What is an ISWC code?

An ISWC, or International Standard Musical Work Code, is a unique ID for a musical work: the underlying composition, the melody and lyrics, not any one recording of it.

The same ISWC covers every version of a song. The original studio cut, a live take, a cover by a different artist, an acoustic re-record, and a club remix all share one ISWC, because they are all the same composition. That is what makes it so useful: it lets publishers, collecting societies, and royalty systems agree on which song they mean, no matter how many times it has been recorded, or by whom.

An ISWC identifies a composition; an ISRC identifies a recording. Two artists covering the same song share its ISWC but have entirely different ISRCs. If you want the two codes compared properly, side by side and against the UPC as well, that lives on the ISRC ⇄ ISWC converter.

Using the finder

How to look up an ISWC

Streaming apps don't show ISWC codes to listeners, so the simplest way to find one is a metadata database like the tool on this page. Start from a recording you already know, and the tool resolves the work behind it.

  1. 1

    Open the finder

    Scroll to the lookup tool above and find the “Find a recording’s ISWC” box.

  2. 2

    Enter an ISRC or track ID

    Paste the recording’s ISRC code (or a SonoVault track ID) into the field. You start from a recording, because that is the thing that carries a code you can copy off a release.

  3. 3

    Read the ISWC

    Press Find ISWC. The composition code appears with its work title. A recording can list several ISWCs when it samples or quotes more than one work.

Many to many

One work, many recordings. One recording, many works.

Almost every guide describes the recording-to-work relationship as one-way: one composition, many recordings. That is only half of it. The mapping fans out in both directions, and the second one is where lookups quietly go wrong.

One work → many recordings

The familiar direction. A composition is recorded once, then covered, remixed, re-recorded, performed live, and re-released, and every one of those is a separate recording with its own ISRC. They all point back to the same ISWC. Enter a work code in the second box above and you get the whole list.

  • The original studio recording
  • A cover by another artist
  • A club remix, an acoustic re-record
  • Every live version ever released
One recording → many works

The direction almost every explainer forgets. A single recording can sit on top of more than one composition, so it carries more than one ISWC. When that happens, taking only the first work code silently drops a rights holder from the picture.

  • A medley performing several songs back to back
  • A track that samples another composition
  • A mashup built from two works
  • An interpolation that quotes someone else's melody

The practical rule: never assume a recording has exactly one work code, and never assume a work has exactly one recording. Treat both lookups as returning a list that happens to be short most of the time.

Reading the code

What an ISWC code looks like

An ISWC is the letter T plus nine digits and a check digit, for example T-070142799-7. The dashes are only there to make it easier to read; the code itself is the T and ten digits with no separators.

T-
Prefix
Marks the code as a musical work; every ISWC begins with T.
070142799-
Work number
Nine digits that uniquely number the composition.
7
Check digit
A final digit used to validate the code.
From the publishing side

Registering a work, and where its ISWC comes from

Songwriters, composers, and publishers rely on ISWCs: they are how performing rights organizations track a composition across every recording and performance, and route songwriting royalties to the right work.

Because an ISWC belongs to the composition rather than the recording, it comes from the publishing side, not a distributor. When you register a work with a performing rights organization or collecting society (such as ASCAP or BMI in the United States, or PRS in the United Kingdom), an ISWC is allocated to that work.

Common questions

Questions people ask about ISWCs

An ISWC (International Standard Musical Work Code) is a unique ID for a musical work: the underlying composition, meaning the melody and lyrics, not any particular recording of it. The same ISWC covers every version of a song: the original studio recording, a live take, a cover by a different artist, and a remix all share the work's ISWC. It is how publishers, collecting societies, and royalty systems identify a song no matter who performs or records it.
Use the free tool above: paste a recording's ISRC (or a SonoVault track ID) into the 'Find a recording's ISWC' box and press Find ISWC. The work code appears with its title. Streaming apps don't show ISWCs to listeners, so a metadata database like this is the easiest way to look one up.
An ISWC starts with the letter T, followed by nine digits and a single check digit, for example T-070142799-7. The dashes are only there for readability; the code is stored as the letter T plus ten digits. The leading T marks it as a musical work code, distinguishing it from other identifiers.
Yes, and this is the part most guides get wrong. A single composition has one ISWC, so it is tempting to assume the mapping is one-way: one work, many recordings. But a recording can also point at several works. A medley performs three compositions back to back; a track that samples or interpolates another song carries the sampled work too. Our lookup returns every ISWC linked to the recording, not just the first.
Because nothing has linked that recording to a work in the data we hold. Our recording-to-work links come from The MLC, and no aggregated source is complete: some recordings simply have not been mapped to a composition yet, and newly released tracks often take a while to appear. A missing ISWC in the tool means we hold no link for it, not that the song has no registered work.
ISWCs are assigned to the composition, not the recording, so they come from the publishing side rather than a distributor. When you register a work with a performing rights organization or collecting society (such as ASCAP or BMI in the US, or PRS in the UK), an ISWC is allocated to that work. You don't request them one at a time the way you might think of a barcode.

Need ISWC data for an app?

This tool is powered by the SonoVault API: ISWC lookup, reverse search, ISRC lookup, and cross-platform track IDs for 90M+ recordings, behind one API key.

ISWC lookup for developersView the API docs →