How to Underline Text on Any Platform (The Complete 2026 Guide)

You want to underline some text. Sounds simple, right? But the answer depends entirely on where you're typing. A Google Doc handles it differently from an Instagram bio, which handles it differently from a WhatsApp message, which handles it differently from a plain text field on your phone.

This guide covers every major platform and method in one place. Find your platform below, follow the steps, and you'll have underlined text in seconds.

The Two Types of Underline

Before diving into platform-specific steps, it helps to understand that there are two fundamentally different ways to underline text:

Rich text underline — The familiar Ctrl+U / Cmd+U shortcut. This works in apps that support formatting: Google Docs, Microsoft Word, email clients, and Slack. The underline is part of the document's formatting and disappears if you paste into a plain text field.

Unicode underline — A combining character (U+0332) attached to each letter. The underline travels with the text wherever you paste it, including platforms that don't support formatting at all: Instagram bios, Discord usernames, WhatsApp messages, and more. This is what our Underline Text Generator produces.

The key difference: rich text underline only works where the app supports it. Unicode underline works everywhere.

How to Underline Text on Instagram

Instagram doesn't offer any built-in text formatting. No bold, no italic, no underline. But Unicode underlined text works perfectly in bios, captions, comments, and DMs.

Steps:

1. Open our Underline Text Generator
2. Type or paste your text
3. Choose an underline style (Classic Underline is the most natural-looking)
4. Tap the copy button
5. Open Instagram and paste into your bio, caption, or comment

Where it works on Instagram:

• Bio (the text under your profile name)
• Captions on posts and reels
• Comments
• Direct messages
• Story text (via paste)

For a deeper walkthrough with 15 ready-made examples, see our full guide: How to Underline Text on Instagram.

How to Underline Text on Discord

Discord supports some Markdown formatting (bold, italic, strikethrough) but has no built-in underline. You have two options:

Method 1: Unicode underline (works everywhere on Discord)

1. Use our Underline Text Generator
2. Type your text and pick a style
3. Copy and paste into any Discord chat, username, or server name

Method 2: Discord's hidden underline syntax Discord actually supports underline via a little-known Markdown extension:

• Wrap your text in double underscores: __your text here__
• This renders as underlined text in chat messages

The double-underscore method only works in chat messages, not in usernames or server names. For those, use the Unicode method.

Read more: How to Underline Text on Discord

How to Underline Text on WhatsApp

WhatsApp supports bold (*text*), italic (_text_), and strikethrough (~text~), but there's no built-in underline formatting.

Steps:

1. Open our Underline Text Generator
2. Type your message
3. Pick an underline style and copy
4. Paste into any WhatsApp chat

Unicode underlined text works in individual chats, group messages, status updates, and your profile name/about section.

Full guide with examples: How to Underline Text on WhatsApp

How to Underline Text on iPhone

On iPhone, how you underline depends on which app you're in:

In Notes, Mail, and Pages (rich text apps):

1. Select your text (tap and hold, then drag the handles)
2. Tap BIU in the formatting bar
3. Tap Underline

In iMessage: iMessage doesn't support underline formatting. Use our Underline Text Generator and paste Unicode underlined text instead.

In Instagram, WhatsApp, TikTok (social media apps): These apps don't have formatting options. Use the Unicode method:

1. Open underlinetextgenerator.com in Safari
2. Type your text and choose a style
3. Tap copy, switch to the app, and paste

For step-by-step screenshots, see: How to Underline Text on iPhone

How to Underline Text on Android

The process on Android mirrors iPhone closely:

In Google Docs, Gmail, Samsung Notes (rich text apps):

1. Long-press to select text
2. Tap the formatting icon (usually A with a line under it or BIU)
3. Tap U for underline

In social media and messaging apps:

1. Open underlinetextgenerator.com in Chrome
2. Type your text and choose a style
3. Tap copy, switch apps, and paste

Detailed guide: How to Underline Text on Android

How to Underline Text in Google Docs

Google Docs has full underline support built in:

• Keyboard shortcut: Ctrl+U (Windows/ChromeOS) or Cmd+U (Mac)
• Menu: Format > Text > Underline
• Toolbar: Click the U button with the underline in the toolbar

Google Docs also supports different underline styles if you need a dotted or dashed look: go to Format > Text > Underline style.

How to Underline Text in Microsoft Word

Word offers the most underline options of any app:

• Keyboard shortcut: Ctrl+U (Windows) or Cmd+U (Mac)
• Toolbar: Click the U button in the Home tab
• Advanced styles: Click the dropdown arrow next to the U button to choose from single, double, thick, dotted, dashed, wavy, and more

For a plain underline where you want to type on top of a line (like a fill-in-the-blank form), use Shift+Hyphen to create an underscore line, or use Tab with underline formatting turned on.

How to Underline Text in Email

Gmail: Select text, then click the U button in the formatting toolbar, or press Ctrl+U / Cmd+U.

Outlook: Same shortcut — Ctrl+U / Cmd+U, or use the formatting toolbar.

Apple Mail: Select text, then go to Format > Font > Underline, or use Cmd+U.

All major email clients support rich text underline. The formatting carries through when the recipient opens the email.

How to Underline Text in a Text Message

Standard SMS text messages are plain text — they don't support any formatting. Your options:

1. Use Unicode underline: Generate underlined text with our Underline Text Generator, then paste it into your messaging app. This works in iMessage, Android Messages, and any other SMS/messaging app.

2. Switch to a rich-text messaging app: WhatsApp, Telegram, and Signal support some formatting. Discord and Slack support full underline via Markdown.

How to Underline Text on TikTok

TikTok bios and comments are plain text only. Use the Unicode method:

1. Open underlinetextgenerator.com
2. Type your text and choose a style
3. Copy and paste into your TikTok bio or comment

Unicode underlined text also works in TikTok usernames, though TikTok has character restrictions that may block some Unicode combining characters in usernames specifically.

How to Underline Text on Facebook

Facebook posts and comments are plain text, but Facebook Messenger supports some formatting.

For posts and comments: Use our Underline Text Generator to create Unicode underlined text and paste it.

For Messenger: Facebook Messenger doesn't have a built-in underline option. Use the Unicode method here too.

For Facebook Notes / Articles: These support rich text formatting including underline via the toolbar.

Quick Reference Table

| Platform | Built-in Underline? | Unicode Works? | Best Method | |----------|---------------------|----------------|-------------| | Instagram | No | Yes | Unicode generator | | Discord | Yes (text) | Yes | Either method | | WhatsApp | No | Yes | Unicode generator | | iPhone Notes | Yes (BIU menu) | Yes | Built-in | | iMessage | No | Yes | Unicode generator | | Android Messages | No | Yes | Unicode generator | | Google Docs | Yes (Ctrl+U) | Yes | Built-in | | Microsoft Word | Yes (Ctrl+U) | Yes | Built-in | | Gmail | Yes (Ctrl+U) | Yes | Built-in | | TikTok | No | Yes | Unicode generator | | Facebook | No | Yes | Unicode generator | | Twitter/X | No | Yes | Unicode generator | | Slack | No native underline | Yes | Unicode generator |

Understanding Unicode Underline Characters

When you use our generator, it attaches a special Unicode character called a combining character to each letter in your text. The most common one is U+0332 (COMBINING LOW LINE), which draws a line beneath the character it's attached to.

For example, the letter "H" followed by U+0332 renders as: H̲

Other combining characters create different effects:

• U+0333 — Double underline (H̳)
• U+0330 — Wavy underline (tilde below)
• U+0324 — Diaeresis below (two dots)
• U+0331 — Macron below (short line)

These characters are part of the Unicode standard and are supported by every modern operating system, browser, and app. They're not a hack or a workaround — they're legitimate text characters that have been in the Unicode standard since version 1.1 (1993).

For a deeper dive into the technical side, see our post on Unicode Underline & Accessibility.

When to Use Underline (and When Not To)

Underlining has a long history in typography. Before word processors, underlining was how typewriters indicated emphasis — it was the only option available. Today, we have bold, italic, color, and size at our disposal, so the role of underline has shifted.

Good uses of underline:

• Drawing attention to a key word or phrase in a social media post
• Making your Instagram bio stand out
• Emphasizing a point in a message
• Creating visual hierarchy in plain text

Be careful with underline on the web: On websites, underlined text is universally associated with hyperlinks. Underlining non-link text on a website can confuse readers.

Accessibility note: Screen readers generally don't announce underline formatting. If you're using underline to convey meaning (not just decoration), make sure the meaning is also conveyed through the words themselves.

For a full comparison of text emphasis methods, read: Underline vs. Italic vs. Bold — When to Use Each

Try It Now

Ready to underline some text? Head to our Underline Text Generator — type your text, pick a style from 53 options, and copy it in one click. It's free, works on every device, and your text never leaves your browser.

Looking for decorative styles? Try our Fancy Underline Text Generator for cute and artistic underline effects, or our Bold Underline Text Generator to combine bold and underline in one step.