YouTube is one of the few large platforms with real text formatting built in. To italicize YouTube comments you wrap the words in underscores, so _this phrase_ posts as italic. The same syntax works in video descriptions and community posts: asterisks for bold, underscores for italic, hyphens for strikethrough.
That native markup is the right tool almost everywhere on YouTube. Unicode conversion is the fallback for the handful of fields YouTube leaves as plain text, and it costs you something every time you use it.
The native syntax
Three markers, typed around the text you want styled.
| Style | Type this | Result |
|---|---|---|
| Bold | *bold text* |
bold text |
| Italic | _italic text_ |
italic text |
| Strikethrough | -struck text- |
|
| Bold italic | *_both_* |
both |
Two things about this surprise people. There is no preview while you type, so the raw markers sit on screen until the comment or description is saved. And there is no Ctrl+B shortcut: the markers are the interface. If you are used to a chat app that formats as you type, YouTube will feel wrong for about ten seconds.
The markers themselves disappear when the text renders. You are not left with visible asterisks the way you would be in a Facebook post.
Which YouTube fields accept which formatting
Formatting support is not uniform across YouTube, and treating it as though it were is the single biggest mistake in most guides on this topic. Check the field, not the platform.
| Field | Native markup | Unicode | Recommended |
|---|---|---|---|
| Comment | Yes | Yes | Native markup |
| Comment reply | Yes | Yes | Native markup |
| Video description | Yes | Yes | Native markup |
| Community post | Yes | Yes | Native markup |
| Video title | No | Yes | Keep plain |
| Channel name | No | Restricted | Keep plain |
Fields not listed here are ones worth testing on your own channel before you rely on them, including playlist descriptions, chapter labels and live chat. Behaviour in those surfaces has changed more than once, and posting a test comment on an unlisted video costs nothing. This guide reflects behaviour observed in September 2026 on the YouTube web client; the mobile apps have historically followed the web on this markup, but YouTube ships changes to the composer without announcements.
Why titles refuse formatting, and why that is fine
The video title is the field YouTube’s search and recommendation systems lean on hardest. It is matched against queries, shown in search results, used in notifications, embedded in share cards and read by voice assistants. Rich text in that field would have to survive every one of those surfaces.
So titles stay plain, and people reach for a font converter to fake it. That trade is worse in a title than almost anywhere else on the internet. A title written as 𝐻𝑜𝑤 𝑡𝑜 𝑏𝑎𝑘𝑒 𝑏𝑟𝑒𝑎𝑑 is not the string How to bake bread. Search cannot match it, autocomplete cannot suggest it, and the words are effectively invisible to the system that decides who sees your video.
If you want a visual accent in a title, an emoji or a bracketed tag does the job without removing the words from the index. Our piece on whether Unicode text hurts your SEO works through what an indexer actually does with these characters.
How to italicize YouTube comments, step by step
- Type the comment normally.
- Put an underscore immediately before the first character of the phrase and immediately after the last one. No space inside the markers.
- Post the comment.
- Read it back. The underscores should be gone and the phrase should be slanted.
If the phrase ends with punctuation, decide whether the punctuation belongs inside the emphasis. _a quiet aside_, renders cleanly. _a quiet aside,_ also renders, but the comma is now italic too, which looks off at small sizes.
Emphasis inside a single word is unreliable. Underscores in the middle of a word are frequently left alone, which is deliberate on most platforms so that file_name_here survives. If you need part of a word emphasised, asterisks behave better.
Formatting a video description
Descriptions accept the same three markers, and this is where they earn their keep. A description is often several hundred words, and a bold line acts as a heading in a field that has no headings.
A pattern that works:
*Chapters*
00:00 Intro
02:14 The mistake everyone makes
*Gear used*
Camera, lens, light
_Affiliate links below. Prices in PKR._Two cautions. The description’s first two or three lines are what shows above the “more” fold and what feeds share previews, so do not spend that space on a bold heading. And any line that contains a link should stay plain, because markers sitting against a URL can break the automatic linking.
Timestamps must also stay plain. YouTube turns 02:14 into a clickable chapter link by pattern matching, and a styled digit is not the digit it is looking for. Unicode’s italic range has no digits at all, which is a separate problem covered in why some italic letters are missing.
Mobile app and desktop differences
The markup itself is identical across clients, because it is parsed server side when the comment or description is saved. What differs is the editing experience.
On desktop you can see the whole description at once, which makes it easy to check that every marker is paired before you save. The Studio description editor is a plain textarea, so nothing autocorrects your underscores.
On the mobile apps the composer is short and the software keyboard is the risk. Two behaviours cause most of the reports that “formatting stopped working on mobile”. Some keyboards convert a pair of straight quotes or a hyphen into typographic punctuation, and a converted hyphen is no longer the strikethrough marker. Others insert a space after punctuation automatically, which breaks the rule that the marker must sit flush against the text.
If a phrase refuses to render on a phone but works when you retype it on desktop, keyboard substitution is almost always the cause. Turning off smart punctuation for that keyboard fixes it.
Live chat is a separate surface again. Chat messages are delivered as plain strings, and neither the markup nor most decorative characters behave predictably there, so treat chat as unformatted.
When Unicode is the right answer on YouTube
There are exactly two situations.
The first is a field with no native option where the text carries no search weight. A short styled phrase in a channel name is the usual example, and even there it costs you: viewers searching your channel by name will not find the styled version.
The second is a specific visual effect the native markup cannot produce. YouTube gives you bold, italic and strikethrough. It does not give you small caps, monospace, double struck or cursive script. If you want a signature line in cursive at the end of a description, conversion is the only route.
The workflow is the same either way. Convert the phrase in the Italic Text Generator, copy it, and paste it into the field. What you are pasting is a run of characters from the Mathematical Alphanumeric Symbols block, described in more detail in our explainer on that block, not a font that YouTube is applying.
What styled characters do to search inside YouTube
YouTube search matches text. It does not normalise mathematical letters back to plain ones, so a styled keyword is a different string as far as the index is concerned.
Concretely:
- A styled word in a title or description will not match a viewer’s query for that word.
- A styled hashtag is a separate hashtag from the plain one, with almost no other videos in it.
- A styled channel name will not autocomplete when a subscriber types your name.
- Comment search inside the Studio moderation tools matches literally too, which makes styled comments harder to moderate.
Keeping the searchable half plain is not a limitation you work around. It is the correct use of the two systems: native markup for emphasis inside indexed text, Unicode only for decoration that nobody needs to find.
Accessibility, honestly
Native markup and Unicode conversion are not equivalent for a listener.
YouTube’s native bold and italic render as styled ordinary characters. A screen reader still receives the letters italic text and reads them as words. Emphasis may or may not be announced depending on the reader and how YouTube marks it up, but the words come through.
Converted characters are different characters. Depending on the reader and its verbosity setting, they can be spelled out one at a time using full Unicode names, read as unrecognised symbols, or skipped. A whole description written in converted characters is unusable for that listener. What screen readers really announce goes reader by reader.
The practical rule for YouTube: if a field supports the native markup, use it. Reach for conversion only when the field has no native option and the text is decorative.
Try it on your own channel
- Upload or pick an unlisted video so nothing is public.
- In the description, write one line as
*Chapters*and one as_Recorded on a phone._ - Save, reload the watch page and confirm both render without visible markers.
- Post a comment on the same video using
_this part only_. - Now paste a converted phrase into the video title and try searching your channel for that word.
The title test is the one worth doing. Watching your own video fail to come back from a search of its own title is a fast lesson.
Troubleshooting
The markers are still visible after posting. Usually a space between the marker and the text, or a marker that was never closed. _ italic _ does not render. _italic_ does.
Only part of the phrase went italic. An extra underscore somewhere in the run closed the emphasis early. Count them: they must pair.
Formatting works in a comment but not in a title. Working as intended. Titles do not support the markup.
A hyphen in the middle of a sentence struck through half the line. Strikethrough uses hyphens, so a dash used as punctuation can open a strikethrough run. If you need a dash, use a comma or parentheses, or space the hyphen so it is not read as a marker.
Formatting renders on the web but not in an older app build. Client versions do drift. Confirm on the current app before assuming the comment is broken.
A converted phrase shows as boxes for some viewers. Their device lacks a font covering that Unicode block. Nothing on your side fixes it, and it is a good reason to keep converted text out of anything load bearing.
Questions people ask about YouTube formatting
How do you italicize a YouTube comment?
Wrap the words in single underscores, so _like this_ posts as italic. Nothing appears styled while you type. The markers vanish and the styling appears once the comment is published.
Does YouTube formatting work in video titles? No. Titles ignore the markup and display the characters literally. Titles are also the field that search leans on hardest, which is why substituting converted characters there does more harm than the styling is worth.
Can you use bold and italic together?
Yes. Wrap the same phrase in both markers, for example *_both_*. Nest them cleanly, because one unpaired marker usually stops the entire run from rendering.
Why did my formatting not apply? In order of frequency: a space between the marker and the word, a marker that was never closed, punctuation sitting inside the markers, or a keyboard that replaced a straight hyphen with a typographic dash.
Should I use a font generator for YouTube instead? Only for fields with no native option, and only for short decorative text. Converted characters are not matched as words by YouTube search and read poorly on screen readers, so they are a bad fit for anything you want found.
The short version
YouTube gives you bold, italic and strikethrough in comments, descriptions and community posts, and nothing in titles or channel names. Use the native markers everywhere they work, because they keep your words as words. Save character conversion for short decorative lines in the fields YouTube leaves plain, and keep every term a viewer might type into the search box in ordinary letters.
Sources for the syntax and field behaviour described here: YouTube’s rich text guidance as summarised by RouteNote and How-To Geek’s walkthrough of comment formatting.
