---
url: "https://questionstar.com/help/question-types/single-line/"
title: "Single Line question type"
description: "With the \"Single Line\" question type you capture compact text entries — including validation, placeholders, format options and pre-filled values."
lastmod: "2026-07-08"
type: "help"
---

# Single Line question type

## About the "Single Line" question type

With the "**Single Line**" question type you can capture free-form entries in the questionnaire — either as plain text or in a more specific format such as numbers, phone numbers, email addresses or regular patterns (regex). This question type is especially suited to compact entries such as:

- names, places or phone numbers
- short open-ended answers (e.g. "What is your favorite dish?")
- codes, ID numbers or other structured data

It's very flexible to use and also offers many configuration options for input validation and display.

## Settings for the Single Line question type

For the "**Single Line**" question type, the following settings are available:

![Settings for the Single Choice question type](/api/media/file/1.-Einstellungen-des-Fragetypen-einfache-Auswahl.png)

1. **Input Size**
Choose the desired width of the input field to match the layout of your questionnaire:**Narrow** – about 1/4 of the questionnaire width**Medium** – about 1/2 of the width**Wide** – full width of the questionnaire**Note**: On smartphones in portrait mode the field is automatically shown at full width — regardless of the selected setting.
2. **Field Prefix and Field Postfix**
Optionally, you can add extra text before or after the input field — e.g. units of measurement, symbols or hints.
Prefix: "approx.", "+49", "from"Postfix: "minutes", "%", "€", "kg"
3. **"Not applicable" option**
This option adds an extra "Not applicable" choice next to the input field.**Recommended use**:
Useful for **required questions** where respondents can still choose not to answer — e.g.:for sensitive or personal topics (e.g. income, age)when no information is available (e.g. "What is your current electricity consumption?")This gives respondents a fair way out without resorting to imprecise or incorrect entries.
4. **Value types (input types) for validation:**
Using the drop-down menu you can define the input type — this ensures that the entry follows specific format rules:

![Value types Single Choice](/api/media/file/2.-Wertetypen-Einfache-Auswahl.png)

**Text** – Free entry with no restrictions (default)**Number** – Only numeric entry allowed**Phone Number** – Entry of a valid phone number**Password** – Entry is masked, e.g. for login fields**Date** (Calendar) – Selection via calendar widget**Time** – Time entry via time widget**Web address**(URL) – e.g. https://www.example.com**Email address** – e.g. name@mail.de**Card Number** – Digits only; all other characters are removed automatically**Pattern (Regex)** – Custom validation with [regular expressions](https://wiki.selfhtml.org/wiki/Regul%C3%A4rer_Ausdruck)
 **Examples**:
 `^[A-Z]{2}\d{6}$` → Two uppercase letters followed by six digits
 `^[A-ZÄÖÜ]{1,3}-[A-Z]{1,2} \d{1,4}E?$` → German license plates with an optional E at the end
5. **Input Field Settings**

## Input Field Settings

![Input Field Settings Single Choice](/api/media/file/3.-Einstellungen-des-Eingabefeldes-Einfache-Auswahl.png)

1. **Initial value**
Here you can define a value that already appears in the input field when the page loads.
 This is especially useful when already known information should be filled in automatically — e.g.:from contact listsURL parametersthrough piping from an earlier answer
 👉 See also: [Reuse answers with piping](/help/advanced-features/piping-reusing-answers)
2. **Highlight element**
 When this option is enabled, the input field is visually highlighted (e.g. with a colored background marker). 
 Useful, for example, for particularly important or central fields.
3. **Placeholder text**
 A gray hint text that appears in the input field while it is empty — e.g.:"Please enter your postal code""Format: DD.MM.YYYY"**Important**: The placeholder text is for guidance only. It is **not saved** and disappears as soon as the respondent starts typing.
4. **Field Prefix / Field Postfix**
 Optional text shown directly before (prefix) or after (postfix) the input field — e.g. "approx.", units of measurement like "kg", "€", "minutes" or symbols like "#". This lets you give entries context and avoid misunderstandings.
5. **Enable custom text field** (e.g. "other")
 Adds an extra free-text field — e.g. when the main question should be supplemented by an open-ended entry. 
 Example:
 "How many hours did you work last month?"Main field: NumberFree-text field: unit (e.g. hours / days)
6. **Answer to "other" required**
 When enabled, the additional text field must be filled in once it has been shown.**Enabled** (default): mandatory entry**Disabled**: the text field may be left empty even when it is shown
7. **Text field placeholder**
 A separate placeholder specifically for the optional free-text field — helpful for clarifying the purpose or expected format of the entry, e.g.: "e.g. minutes", "please explain in more detail". 
 Here too: the text is only a hint and is **not saved**.

### Additional options depending on the input type:

Depending on the selected **value type**, further specific settings are available in the properties dialog:

- **Number:****Minimum Allowed Value:** Lower limit for the entry (e.g. "0" for no negative values)**Maximum Allowed Value:** Upper limit for the entry (e.g. "100" for percentages)**Number of Decimals:** Defines how many decimal places are allowed (e.g. "2" for monetary amounts)

![Number field type](/api/media/file/4.-Feldtyp-Zahl.png)

- **Password:****Minimum Password Length:** Sets how many characters the password must have at minimum (e.g. "8" for secure entries)

![Password field type](/api/media/file/5.-Feldtyp-Passwort.png)

- **Date:****Date Format:** By default the format is automatically adapted to the interface language (e.g. "dd.mm.yyyy" for German). Alternatively, you can force the format:`dd.mm.yyyy``mm/dd/yyyy``dd/mm/yyyy`**Default Date Value:** A start date that already appears in the field when the survey loads — e.g. a fixed date like `01.01.2025`**From Date / To Date:** Allows only entries within a specific period (e.g. for bookings, applications, validity ranges)

![Date field type](/api/media/file/6.-Feldtyp-Datum.png)

- **Time:****Initial Value:** A time that is already pre-filled — e.g. `08:00` for a default time

![Time field type](/api/media/file/7.-Feldtyp-Zeit.png)

- **Regex:****Input Pattern (regexp):** Enables flexible validation with [regular expressions](https://wiki.selfhtml.org/wiki/Regul%C3%A4rer_Ausdruck) — e.g.:**Postal code (5 digits):** `^\d{5}$`**IBAN (simplified check):** `^[A-Z]{2}\d{2}[A-Z\d]{1,30}$`**German license plates:** `^[A-ZÄÖÜ]{1,3}-[A-Z]{1,2} \d{1,4}E?$`

![Regex field type](/api/media/file/8.-Feldtyp-Regex.png)

## Example of a Single Line question

To give you a better sense of a typical use of this question type, we've prepared a concrete example:

*[Interaktiv:  — siehe HTML-Version der Seite]*

[Open preview in new window](https://app.questionstar.com/preview-panel/5e36fd96-ce12-45b1-993c-0424fd5f12df/9e60dbc3-6704-4764-a868-f974f8ceb66f)