Glossary
What is form autofill?
Form autofill is filling web form fields automatically from saved or generated information. Browsers autofill names, addresses and cards; extensions fill custom fields; AI agents read each field's label and limit, then write a fitting answer, such as a product description cut to a directory's character limit.
Three levels
| Level | Handles |
|---|---|
| Browser autofill | Name, email, address, card (with permission) |
| Extension with saved profile | Repeated custom fields: tagline, description, URL |
| AI agent | Any field: reads label and limit, writes a fitting answer |
Why limits matter
Directory forms vary widely. Across 108 forms we parsed, tagline limits had a median of 160 characters and description limits a median of 1,000, ranging from under 100 to 5,000. Pasting one description fails or gets cut mid-sentence. Good autofill reads the limit and writes to fit.
What shouldn't be autofilled by an agent
Passwords, payment details and identity documents should come from you or your password manager, not be typed by an AI agent from plain text.
Example
An agent fills a directory form: product name and URL from the profile, a 58-character tagline for a 60-character limit, a 300-character description for a 300 limit, the right category from a dropdown, and the logo upload. It leaves the payment option for the founder.
FAQ
Is AI form filling accurate?
With good product information and field limits, yes; review important submissions.
Can autofill handle dropdowns and uploads?
Agents can; basic browser autofill usually can't.
Should an agent autofill passwords?
No. Use your password manager.