Mark your required fields before users start typing
Show required fields up front
Users abandon forms when they discover requirements after filling in optional fields. Mark required fields before anyone types. Use a consistent indicator — typically an asterisk — next to the label, not buried in help text.
Place the indicator on the same line as the field label. "Email address *" works. "Email address (required)" takes longer to parse. Asterisks scan faster than words.
Use one pattern across all forms
Pick asterisk-for-required or label-for-optional. Don't switch between forms on the same site. If contact forms mark required fields with asterisks, login forms should too.
Most forms have more required fields than optional ones. Mark required fields. If you have mostly optional fields, mark those instead and leave required fields unmarked. Choose the pattern that requires fewer indicators.
Explain the indicator once per page
Add a single line of text before the first field: "* indicates required field" or "All fields required except those marked optional." Don't repeat this explanation above every form on your site. Once per page is sufficient.
Place this explanation where users will see it before they start filling fields — directly above the first input, not at the bottom of the form near the submit button.
Don't rely on color alone
Red asterisks fail for colorblind users. Use shape (the asterisk itself) as the primary indicator. Color can reinforce, but shape must carry the meaning.
Bold labels for required fields also fail on their own. Pair weight changes with a symbol.
Validate required fields on submit, not on blur
Don't show "This field is required" errors while users are still filling out the form. Wait until they attempt to submit. Premature validation creates false urgency and disrupts the user's mental model of form completion.
When validation does trigger, return focus to the first empty required field. Make error messages appear next to the field they reference, not in a summary block users have to cross-reference.
Match your CMS field configuration
If your CMS marks fields as required in the admin interface, your public-facing forms should use identical visual indicators. Staff switching between editing and reviewing published forms shouldn't need to decode different systems.
Document your required field pattern in your style guide. Include the HTML snippet and CSS if your forms are hand-coded. Include the CMS configuration setting if you use form builder modules.
Test with incomplete submissions
Fill out a form on your site but skip one required field. Submit it. Does the error message clearly identify which field needs attention? Does the page scroll to that field? If you're hunting for what went wrong, your users will too.
Required field indicators prevent that hunt. They work when they're visible before anyone starts typing.