An author biography provides context, not a complete life history. Its best details help readers understand your connection to the work. Start with the place where the bio will appear: a book jacket, event page, website, or guest article. Each setting gives you a different amount of space.
Build a small fact bank
List your published work, relevant experience, subjects you return to, and one personal detail you are comfortable sharing publicly. Check titles, dates, and descriptions against reliable records. An accurate modest credential is stronger than a sweeping claim that cannot be supported.
You do not need a prize or a long publication list to write a useful bio. The research, practice, or lived experience behind a particular project may be more relevant to its readers.
Write the short version first
Try two sentences: who you are and what you write; then a relevant detail that helps someone remember you. Add a website only when the publication allows it. Use first or third person according to the host's requirements, and keep that choice consistent.
Fictional example: Mara Ellis writes family mysteries set in small coastal towns. Her stories explore the objects people keep and the histories they leave untold.
This example makes a clear promise about subject and tone without inventing authority.
Expand with purpose
For a longer version, add a book title, background that informs the writing, and a human detail that fits your boundaries. Avoid packing every hobby into the final sentence. Readers should leave with a clear impression rather than a catalogue.
Keep approved versions in one document labeled by approximate length and intended use. Revisit them when a new book appears or a detail changes. Before sending a bio, confirm that every claim is still accurate and that the wording fits the audience. Consistency helps, but a conference program may need different details from a children's book page.