Copyediting (or simply 'editing') is a far more extensive practice that consists of both correcting errors and creative rewording. A document should be edited after it has been written, and its content confirmed, but prior to its being proofread. Copyediting one's own work is usually a little more successful than proofreading one's own work, but it is still very often beneficial to have a second pair of eyes look over your work. The problem with checking a piece of writing that you have just written is that, again, you see what you expect to see, and presuppose knowledge that you need your reader to have. An experienced editor and second reader is far better placed to highlight areas in which the writing is unclear, repetitive or unnecessarily convoluted.

The copyediting process can include the reduction or increase of the word count, creative rewriting, the amending of text to ensure clarity or the deletion of text to make the piece concise. Copyediting can also include the addition of small amounts of text to expand on important points or 'straighten out' unclear sections.