How to Build a Dynamic Multi-Step Form with Real-Time Email Validation

A multi-step data entry form for Google Sheets, built so the form itself is configured from a sheet rather than from code. Long single-page forms get abandoned; splitting them into steps with a progress indicator, and validating as the user goes, gets far more of them finished.

What it does

The form walks the user through several steps with a progress indicator. Email addresses are checked against existing entries in real time, so the user sees "Email Available" or "Already Registered" before submitting rather than after. Dropdowns can depend on each other — pick an Industry and the Role list narrows to match — and photos, CVs or documents upload into Google Drive. A Config sheet controls which fields exist, which step they sit on and what options they offer, so the form can be restructured without opening the code.

Highlights

• Multi-step navigation with a progress indicator
• Real-time email duplicate check with instant feedback
• Dependent dropdowns driven by the sheet
• File uploads to Google Drive for photos, CVs and documents
• Config sheet controls fields, steps and options — no code change
• Deploys as a Google Apps Script web app in minutes
• Demo data setup function so you can see it working immediately

Who it is for

HR teams taking job applications, schools handling admissions, event organisers running registrations, and Apps Script developers who want a form engine they can reconfigure per client from a spreadsheet instead of rewriting the front-end each time.