According to the guidelines developed by the U.S. Technology Transformation Services (TTS), the recommended line length should be between 45-75 characters, including spaces. From an accessibility standpoint, lines longer than this range are hard to follow in large blocks of text. On the other hand, short lines are also not the best solution. Due to their abrupt endings, users' eyes have to move back and forth too often. Eventually, users get tired, and their attention wanes. To avoid this, stick to the suggested range.

Note that headlines, captions, and labels don't need to adhere to the same line length considerations and can be shorter.