Strong marks a span of text as having strong importance. It renders as bold in most output formats. It is written by wrapping the text with double ** or __ on each side.
**This text is strong.**
__This text is also strong.__
This text is strong.
This text is also strong.
Best Practice
- Use
**rather than__as the standard form —**is unambiguous in all contexts and works reliably mid-word. - Reserve strong for genuinely important content: warnings, key terms, critical steps. Do not use it for visual decoration.
- Avoid bolding entire sentences; strong loses its impact when applied too broadly.
Notes
** vs __ Delimiters
Both delimiters produce identical output, but __ has the same mid-word restriction as _ for emphasis — it will not open or close inside a word. ** has no such restriction and is the safer general-purpose choice.
Combining with Emphasis
Strong and emphasis can be combined by using *** on each side:
***This text is bold and italic.***
When mixing * and _, use consistent pairing to avoid parser surprises.
Markdown Flavour Support
Supported by all major flavours.
Flavour Support Detail
| Flavour | Support | Notes |
|---|---|---|
| Original Markdown | Yes | Both ** and __ defined in the original spec. |
| CommonMark | Yes | Precisely specifies delimiter run rules for strong. |
| GitHub Flavored Markdown | Yes | Inherits CommonMark rules. |
| Pandoc Markdown | Yes | Full support. |
Practical Examples
- Safety warning in a hiking guide: Bold draws the eye immediately to critical information a reader should not miss.
**Never leave the marked trail after dark.** The terrain becomes dangerous without visibility.
Never leave the marked trail after dark. The terrain becomes dangerous without visibility.
- Key ingredient call-out in a recipe: Use strong to highlight the one ingredient that makes the dish — the thing a reader must not substitute.
The secret is **smoked paprika** — not sweet, not hot, specifically smoked.
The secret is smoked paprika — not sweet, not hot, specifically smoked.
- Announcing an important date in a club newsletter: Bold signals at a glance which information readers need to act on.
Our next meeting is **Saturday 14 June** — please bring your membership cards.
Our next meeting is Saturday 14 June — please bring your membership cards.