How to Bold, Italicize, and Strikethrough Text in Markdown

If you're writing in Markdown, the first thing you'll want to master is emphasis. Adding emphasis is how you tell readers what matters — a keyword, a warning, a deleted line, or a term you're defining. This guide walks through markdown bold and markdown italic syntax, plus GFM markdown strikethrough, with copy-paste examples you can try in our online viewer. If you want a broader reference afterward, see our Markdown cheat sheet.

Quick Reference Table

Before diving into the details, here's a one-glance summary of every emphasis style covered in this guide:

Effect	Syntax	Example
Italic	*text* or _text_	*hello* → hello
Bold	**text** or __text__	**hello** → hello
Bold + Italic	***text***	***hello*** → hello
Strikethrough (GFM)	~~text~~	~~hello~~ → hello
Inline code	`text`	`hello` → hello

How to Italicize Text in Markdown

Markdown italic uses a single wrapping character. You can wrap your text in either one asterisk or one underscore on each side:

This word is *italic*.
This word is _italic_ too.

Both lines render identically. The choice between * and _ is mostly stylistic, but as you'll see below, they behave differently inside words. For most writers, the asterisk is the safer default because it works in more situations — that's why you'll see it dominate in our GitHub-flavored Markdown guide.

How to Bold Text in Markdown

For markdown bold, double the wrapping character. Use two asterisks or two underscores:

This is **bold** text.
This is __bold__ text too.

That's the entire rule. The tricky part isn't the syntax itself — it's how bold interacts with surrounding punctuation, spaces, and other emphasis. Keep reading.

Combining Bold and Italic

When you want both bold and italic at once, triple the asterisk (or mix underscores and asterisks). The cleanest form is three asterisks on each side:

This is ***bold and italic***.

You can also mix, though it's less readable:

This is _**also bold and italic**_.
This is *__also bold and italic__*.

All three render the same. Stick with ***text*** for consistency — it's the easiest to scan when reading raw Markdown.

Markdown Strikethrough (GFM)

Strikethrough isn't part of the original Markdown spec — it comes from GitHub Flavored Markdown (GFM) and uses two tildes:

This is ~~deleted~~ text.

Most modern Markdown viewers, including ours, render GFM by default, so markdown strikethrough will work out of the box. If you're targeting a stricter parser, double-check that it supports the ~~ syntax before relying on it.

Asterisks vs Underscores: The One Difference That Bites People

Here's the rule that catches almost every newcomer: underscores do not work inside a word, but asterisks do.

un*frigging*believable   → un*frigging*believable renders as: un<em>frigging</em>believable
un_frigging_believable   → renders literally as: un_frigging_believable

In other words:

The word fan*_freaking_*tastic works with asterisks.
The word fan_freaking_tastic does NOT work with underscores.

Underscores only trigger emphasis when they're at a word boundary — adjacent to whitespace, punctuation, or the start/end of the line. Asterisks are more permissive and work mid-word. This is why, for markdown bold and italic alike, asterisks are the recommended default unless you have a specific reason to use underscores.

Nesting and Ordering Rules

Emphasis can nest, but the order matters and mismatches break rendering. A few reliable patterns:

**bold with an *italic* word inside**
*italic with a **bold** word inside*
~~struck with **bold** inside~~

The key rules:

1. Close in the reverse order you open. If you open bold then italic (** then *), close italic then bold (* then **). Think of it like parentheses.
2. Don't overlap. *bold and **italic* broken** is invalid — markers must nest cleanly.
3. Triple markers are shorthand, not magic. ***text*** is equivalent to opening bold+italic and closing both; it still follows the nesting rule.

When in doubt, render it in the editor and check the preview pane.

Inline Code vs Emphasis

A common point of confusion: backticks (`) and emphasis markers do completely different things. Backticks produce inline code, which displays your text verbatim in a monospace font and ignores any Markdown inside it:

Use the `**bold**` syntax for bold.

Inside the backticks, the ** is shown literally — it is not rendered as bold. Backticks are the right choice when you're showing someone the syntax itself (as this guide does throughout). Emphasis markers are for styling prose. For a deeper treatment, see our Markdown code blocks guide.

Common Mistakes to Avoid

Even experienced writers hit these. Run through the list when something isn't rendering:

Mismatched markers. Opening with * and closing with _ (or vice versa) does nothing:

This *does not work_.

Use the same character on both sides.

Stray spaces inside the markers. A space just inside the opening or closing marker cancels the emphasis:

This is ** not bold **.

The ** here is treated as literal asterisks because of the adjacent spaces. Keep text flush against the markers.

Forgetting the GFM tilde count. A single tilde (~text~) does not strike through in standard GFM — you need two (~~text~~).

Underscores mid-word. As covered above, my_var_name won't render the middle as italic because underscores don't split words. This is actually desirable in technical writing (variable names stay intact), which is why the rule exists.

Mixing code and emphasis. Don't try to bold part of an inline code span — backticks escape everything inside them. Style the surrounding prose instead.

Frequently Asked Questions

Can I nest strikethrough inside bold?

Yes. GFM allows ~~struck and **bold**~~, and most renderers handle the combination cleanly. Just follow the nesting rule — close in the reverse order you opened.

Which should I use: asterisks or underscores?

Use asterisks as your default. They work mid-word, they're more widely supported across parsers, and they're the convention in nearly all published Markdown style guides. Reserve underscores for cases where you specifically want emphasis to respect word boundaries.

Why is my bold text showing literal asterisks?

Almost always a spacing problem. Check for a space directly after the opening ** or before the closing **. Removing the stray space fixes it immediately.

Does markdown strikethrough work everywhere?

It works in any GFM-compliant renderer — GitHub, most modern static site generators, and our viewer. It does not work in parsers that only implement the original 2004 Markdown spec. If you're unsure about your target, test it first.

Wrapping Up

Mastering markdown bold, italic, and strikethrough is mostly about consistency: pick asterisks as your default, mind your spacing, and remember that underscores won't split a word. With the table and patterns above, you have everything you need to format prose cleanly — and you can paste any example straight into the editor to see it rendered live. For the bigger picture of where emphasis fits into the language as a whole, our what is Markdown overview is a good next stop.