Is there some web page or Unix command line tool where I can paste the text of a license, and it would match it against a database of well-known open source licenses to tell me which one it is?

For example, the SPDX project already has an excellent database, I'm just looking for an easy front-end for this purpose.

  • 1
    The usual problem isn't identifying the licence given the text, it's finding some kind of licence declaration in the first place. Do you have working examples of licences which are clear, but you can't tell which licence they are?
    – MadHatter
    Commented Jul 21, 2019 at 9:05
  • 5
    GitHub uses the Licensee tool (written in Ruby) to determine project licenses.
    – amon
    Commented Jul 21, 2019 at 10:36
  • 1
    Licensee is just what I was looking for (even better in fact, since it can find LICENSE/COPYING/etc. files in the current directory by itself). For license files with custom text it even lets you do things like licensee diff COPYING --license MIT which makes it say Similarity: 95.29% and show the diff. This used to take minutes of tedious work, now it takes a few seconds and does a more reliable comparison than I could do myself. Perfect.
    – Lassi
    Commented Jul 21, 2019 at 10:51
  • 3
    @amon I guess this should be an Answer.
    – Brandin
    Commented Jul 22, 2019 at 5:17
  • 1
    It's a great answer. I know "recommend a tool" questions are frowned upon but I couldn't figure out how else to phrase it.
    – Lassi
    Commented Jul 22, 2019 at 7:57

1 Answer 1


In order that this question can have an answer accepted, but given that Amon doesn't seem minded to write it, I'm repeating his/her answer verbatim as community wiki. Amon, if you do want to write it up, flag me or a mod to remove this answer.

GitHub uses the licensee tool, which is written in Ruby, to determine project licences.

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