Permissions and Fair Use

What Is Fair Use?

Under U.S. Copyright Law, fair use permits the use of copyright-protected content without permission in limited circumstances. Essentially, authors may be able to reuse small amounts of third-party material (meaning, someone else’s material) provided they can be considered fair use.

How Is Fair Use Determined?

Fair use is a common defense for using very small amounts of material from another source, such as a quote or line of code. But please be aware, there’s no exact legal standard—no word count or percentage.

For your use to be considered fair use:

• The borrowed material should illustrate a point central to your work. Excerpts without meaningful context would not be considered fair use.
• Transformative uses that add something new and do not merely replicate the original use are more likely to be considered fair use.
• Never use more than absolutely necessary.
• The length of the original is important. Fair use would more likely apply to three (3) sentences from a novel versus three (3) lines from a poem.
• Using the most important part (the "heart") of a work, even if it's minimal, may not be fair use.
• The proportion of third-party material in your work should be small compared to your own content. You should not rely on one or two sources heavily; better to spread reused materials among as many relevant sources as possible.
• Consider if your use will harm the existing or future market for the original work.

Some Tips on Permission

You should treat third-party permissions requests consistently. If you ask for permission to reuse a one-paragraph excerpt from one party, it’s appropriate to ask for permission for all other similar-sized excerpts.

If you believe your use is fair use, our suggestion would be not to ask permission for the quoted content. If you request permission but your request is declined—or even if you receive no response at all—it would be difficult for you to claim fair use once you’ve already requested permission.

Some open-source and Creative Commons licenses may not allow you to reuse content in an O’Reilly product, since we require broad rights to publish and distribute our content. Please review all licenses carefully before deciding to use third-party content.

For more information, we recommend starting with the U.S. Copyright Office’s page on fair use.