Required vs Optional Form Questions: How to Decide

Every red asterisk on a form is a tiny demand placed on your user.

Make too few fields mandatory, and you end up with a database full of useless, incomplete records.

Make too many questions required, and people simply abandon the page or type keyboard gibberish just to hit the submit button.

Finding the exact right balance between required and optional questions dictates whether your form actually does its job.

The advantages and risks of making form fields required

Mandatory fields exist to protect your core process. When you mark a field as required, you guarantee that the form cannot be submitted without that specific piece of data. This strictness is incredibly useful when a missing answer would break the next step in your workflow.

If you are running a medical clinic, you cannot process a new patient without their legal name and date of birth. If you are sending a physical product, a mailing address is non-negotiable. Required fields enforce these hard boundaries. They prevent careless omissions and ensure your team has exactly what they need to act.

But this control comes at a steep price.

Every required field increases the cognitive load of your form. Cognitive load is the total amount of mental effort being used in the working memory. When users see a long wall of mandatory questions, they immediately calculate the time and effort required to finish. If that effort outweighs their desire for whatever is at the end of the form, they will leave.

Worse than abandonment is the risk of fabricated data. When a user encounters a required question they consider too invasive, irrelevant, or difficult to answer, they often invent a response.

Phone number collection

• ❌ Weak: Work Phone Number (Required, no explanation given).
• ✅ Strong: Work Phone Number (Optional, with a note: Only used if we need to call you about your delivery).

Why it works: Forcing a phone number when the user prefers email leads directly to fake entries like 555-555-5555.

When you review your database and find dozens of entries that say "N/A", "asdf", or fake phone numbers, your required fields have failed. You forced the user to provide an answer, but you degraded the integrity of your data in the process.

You must also consider the context of the user's environment. A person filling out an application on a mobile phone while waiting for a train has very little patience for mandatory long-form text fields. The physical environment limits their capacity to type out detailed answers. If that field is required, they will either close the tab or provide a rushed, useless response.

Why optional questions preserve completion rates and user trust

Optional questions are the pressure relief valves of your form. They allow you to ask for valuable, detailed information without holding the entire submission hostage.

When you mark a field as optional, you explicitly communicate respect for the user's time and privacy. This builds immediate trust. If a software company asks for a birth date on a newsletter signup, making it mandatory feels invasive. The user wonders why a newsletter needs their age. Making that exact same field optional changes the tone entirely. It signals that the company would like to know, perhaps for a birthday discount, but the user remains in control.

Expert tip: Use optional fields to capture high-quality qualitative feedback. A motivated user will gladly write a detailed paragraph in an optional text box, whereas forcing everyone to write a paragraph guarantees you will receive mostly single-word answers.

Optional questions also respect Hick's law, a psychological principle stating that the time it takes to make a decision increases with the number and complexity of choices. When a user scans a form and sees that half the questions are optional, the perceived complexity drops drastically. They categorize the optional questions as secondary tasks. They can focus entirely on the mandatory core, completing the form faster and with less frustration.

In practice, the data you get from optional fields is often your most valuable.

Because the response is voluntary, the user has self-selected as someone with something genuine to say. If you run an event and include an optional field for dietary requirements, the people who fill it out care deeply about the answer. The people who skip it do not. If you made it required, you would force hundreds of people to type "None," wasting their time and cluttering your spreadsheet.

Feedback requests

• ❌ Weak: How can we improve our service? (Required text area).
• ✅ Strong: Anything else you'd like us to know? (Optional text area).

Why it works: Forcing feedback annoys happy customers who have nothing to add.

You also preserve completion rates by giving users an out when they simply do not know the answer. In B2B sales forms, asking for a company's exact annual revenue is common. Many junior employees downloading a whitepaper do not know that number. If the field is required, they abandon the download. If it is optional, you still capture the lead. You trade one missing data point for a complete contact record.

A framework for deciding which questions must be mandatory

Deciding between required and optional is not an exact science, but it follows a predictable logic. You must separate the data you absolutely need from the data you simply want.

The most effective way to do this is to define the minimum viable submission. What is the absolute bare minimum amount of information required for the next step in your process to occur? Anything outside of that minimum viable data set should default to optional.

When digitizing old paper workflows - like moving a physical intake form to Google Forms - the instinct is often to make every single question mandatory. Paper forms usually present a grid of empty boxes, and administrators hate seeing them blank. But digital forms behave differently. A digital form cannot be handed in incomplete if the required toggles are set. You must evaluate every legacy question before turning on the required switch.

Use the following decision matrix to evaluate your fields based on the type of form you are building.

To apply this framework, ask three strict questions of every field on your form:

1. Will the process break without this? If you cannot ship the box, call the patient, or bill the client without the answer, the field must be required.
2. Are we going to use this data immediately? If you are collecting "Company Size" just to look at a pie chart at the end of the year, make it optional. Do not force users to do work for your internal vanity metrics.
3. Does the user benefit from answering? If providing a phone number means they get SMS delivery updates, they benefit. If providing it only means your sales team will cold-call them, only you benefit. When the benefit is entirely yours, lean toward making it optional.

This evaluation is especially critical when migrating long questionnaires. If you are converting a complex survey into a Google Form, you will likely find that half the questions can be made optional without hurting the core objective of the research.

Visual design standards for marking required versus optional fields

Once you have decided which fields hold which status, you must communicate that status to the user instantly. If a user cannot tell what is required until they click Submit and see a wall of red error messages, your design has failed.

The visual indicator must be obvious before the user clicks into the first text box. The industry standard for a required field is the red asterisk (*), typically placed immediately after the field label.

However, relying solely on the asterisk has limitations.

First, not all users understand what the asterisk means, especially in less tech-savvy demographics. Second, screen readers for visually impaired users handle asterisks inconsistently. Some read it out loud as "star", some say "asterisk", and some skip it entirely unless the form is coded with specific ARIA accessibility labels.

Because of these limitations, modern form design often shifts the burden of proof. Instead of marking what is required, you mark what is optional.

If you have a form where eight out of ten questions are required, putting eight red asterisks on the page creates visual clutter. It makes the form look intimidating. In this scenario, it is often cleaner to remove the asterisks entirely and explicitly write the word (optional) next to the two fields that can be skipped.

Visual label placement

• ❌ Weak: Address Line 2 (No indicator, leaving the user guessing if an apartment number is mandatory).
• ✅ Strong: Address Line 2 (optional) (Explicitly stated in the label text).

Why it works: Plain text removes all ambiguity and requires no decoding by the user.

When deciding on your visual design standard, follow the rule of the minority. Whichever type of field is in the minority should get the visual label.

If you are using Google Forms, the platform handles the required indicator for you. When you toggle the Required switch at the bottom right of a question block, Google automatically appends the standard red asterisk to the question title. It also adds a note at the top of the form stating "* Indicates required question".

You cannot natively change this red asterisk to the word "(optional)" in Google Forms. If you want to explicitly mark a Google Form question as optional, you must leave the Required toggle off, and manually type (optional) into the question title yourself.

Alternative strategies to avoid forcing user responses

The debate between required and optional often traps form builders into binary thinking. You do not always have to choose between forcing an answer and risking a blank field. You can use form logic and structural design to gather data without relying on mandatory constraints.

The most powerful alternative is conditional logic, also known as branching.

Instead of presenting twenty questions on a single page and making half of them optional, you ask one required multiple-choice question. The answer to that question dictates what appears next. This bypasses the need for optional fields entirely, because the user only ever sees questions that are directly relevant to their situation.

Using branching logic

• ❌ Weak: If you selected 'Other' above, please explain. (An optional text field sitting visibly on the page for everyone).
• ✅ Strong: The text field is completely hidden. It only appears, as a required field, if the user specifically clicks the Other radio button.

Why it works: It removes irrelevant fields from the screen, lowering cognitive load for everyone else.

In Google Forms, this is accomplished using the Go to section based on answer feature. By breaking your form into sections, you route users down personalized paths. A user who says they are a "Current Customer" bypasses all the introductory sales questions and goes straight to support. Every field they see on the support page can be required, because you already know it applies to them.

Another strategy is progressive disclosure.

This involves breaking a long process into multiple, smaller steps. Instead of asking for twenty data points upfront, you ask for the core three requirements first (name, email, password) to create the account. Once the account is created, you prompt the user to complete their profile later. The initial form has a 100% completion rate because you only asked the mandatory minimum. The secondary data is collected gradually over time, avoiding the friction of a massive initial questionnaire.

You can also rely on smart defaults.

If you know the majority of your users will answer a question a certain way, pre-fill that answer for them. If your software is only available in the United States, pre-select "United States" in the country dropdown. The field is technically required, but the user does not have to expend any effort to fill it out unless they need to change it. This satisfies the database requirement without taxing the user.

Finally, consider replacing required text fields with structured multiple-choice options. Often, administrators make a text box required because they need a specific type of answer, but users hate typing out long responses. If you convert that required open text box into a required dropdown menu, you drastically reduce the friction. The user still has to provide the mandatory data, but clicking a single option requires a fraction of the effort of typing a sentence.

FAQ

Is it better to mark required fields or optional fields?

It depends entirely on the ratio of your form. If the vast majority of your fields are required, it is visually cleaner to only mark the few optional fields with the text "(optional)". If most of your fields are optional, you should mark the critical mandatory fields with an asterisk to highlight the minimum required effort.

Does making questions required increase form abandonment?

Yes, strictly forcing answers increases abandonment rates, especially for sensitive or high-effort questions. When users encounter a mandatory field they cannot or do not want to answer, their only choices are to lie or close the page. Keeping non-essential fields optional prevents users from hitting these frustrating dead ends.

How do you make a question optional in Google Forms?

Every new question you add in Google Forms is optional by default. To ensure it stays optional, verify that the Required toggle switch located in the bottom right corner of the specific question box is flipped to the off (gray) position. You can also manually type the word "(optional)" into the question title to make it perfectly clear to the respondent.

What is the best symbol to represent a required field?

The red asterisk (*) placed immediately after the field label is the universally recognized symbol for a mandatory question. While it is the standard, you must ensure your form software associates the symbol with proper accessibility tags so that screen readers can announce it to visually impaired users.

Deciding between required and optional questions ultimately comes down to respecting the person on the other side of the screen. When you demand only what you truly need and make everything else voluntary, you build forms that people actually finish. If you need to turn a complex set of legacy requirements into a modern digital workflow, Doc2Form can automatically convert your existing documents into Google Forms, helping you quickly test which fields should stay mandatory and which can finally be made optional.