Invisible text: blank characters to copy and when to use them
Which character to use on WhatsApp, Instagram or in your email, and when it can backfire
Invisible text is a character that the system counts as text but that doesn’t show on screen.
It looks like an empty gap. To the app, though, something is written there.
That’s why it works where you can’t leave a field blank: a “nameless” name on WhatsApp, a message that looks empty or a line break on Instagram.
And it has a lesser-known use in email: padding the preheader so the body of the message doesn’t sneak into the inbox.
How does invisible text work?
Cada letra, número o símbolo tiene un código en Unicode, el estándar que usan móviles y ordenadores para mostrar texto.
Some of those codes don’t draw anything. They are special spaces, fillers or joining marks between letters.
The normal space on your keyboard doesn’t work for this. Many apps trim it at the beginning and end, or don’t accept a field that contains only spaces.
A character like the Hangul filler (U+3164) doesn’t get trimmed. The system treats it not as a space but as a letter with nothing drawn.
Don’t confuse it with whitespace in design. That’s the breathing room you leave around the elements of a page or an email.
Invisible text is a specific character that you copy and paste.
Invisible text to copy and paste
These are the most commonly used blank characters.
To copy one, select only the gap between the brackets and paste it wherever you need it. On a computer, double-clicking inside is usually enough.
| Character | Code | Where it works best | Copy it |
|---|---|---|---|
| Hangul filler | U+3164 | Names on WhatsApp, Free Fire and games | [ㅤ] |
| Braille blank | U+2800 | WhatsApp messages, line breaks on Instagram | [⠀] |
| Zero-width space | U+200B | Separating words unnoticed, breaking long links | [] |
| Non-breaking space | U+00A0 | Keeping two words from being split across lines | [ ] |
| Zero-width non-joiner | U+200C | Preheader padding in emails () | [] |
| Figure space | U+2007 | Aligning numbers in text tables | [ ] |
As you can see, they don’t all do the same job. The zero-width ones take up no space: they’re for joining or separating text, not for “writing” an empty name.
For a blank name or message, you need a character with width, like the Hangul filler or the braille blank.
Control what’s read next to your subject line
With Mailrelay, you write your own preview text and send up to 80,000 emails a month for free, with human support on every plan.
Which one to use on WhatsApp, Instagram or Free Fire?
Each app filters characters in its own way. What works today may stop working after an update. These are the most common combinations:
- Invisible name on WhatsApp: paste the Hangul filler (ㅤ) into the name field. If the app rejects it, try two in a row.
- Empty message on WhatsApp: WhatsApp won’t let you send a message with no text, but it will let you send one with the braille blank (⠀). It arrives as a bubble that looks empty.
- Line breaks on Instagram: put a braille blank on its own on the line you want to leave empty, in your bio or caption.
- Usernames in Free Fire and other games: the Hangul filler is the most popular choice for separating words or leaving gaps in the name.
Would you rather format what people do see? The post on bold, italics and strikethrough on WhatsApp covers all 8 formats.
And if you’re after faces, check out the entries on kaomoji, with almost a hundred to copy, and emoji.
The invisible text trick in the preheader
In the inbox, next to the email subject line, there’s a preview line: the preheader.
If you keep it short, Gmail, Outlook or Apple Mail fill the gap with the first words of the body.
And that’s where things like “View in browser” or the logo’s alt text tend to show up.
To avoid this, a string of invisible text is added right after the preheader.
The email client counts it as text, fills the line with it and doesn’t pull from the body.
The most widespread combination repeats ͏ several dozen times. They are U+034F, U+200C and a non-breaking space.
Litmus, one of the industry’s references in email testing, explains this technique on its blog.
That said, you don’t need it in every send. If your preheader already fills the line, the padding adds nothing.
The preheader entry tells you how many characters fit.
And it’s a good idea to test it first in several email clients, because each one cuts off the preview at a different point.
Can invisible text cause problems?
Yes, and more so in email than anywhere else.
Hidden text is a classic technique of fraudulent email, so spam filters scrutinize it closely.
In January 2019, the security company Avanan described the Z-WASP attack.
These were phishing emails that inserted zero-width spaces inside links so that Office 365 wouldn’t recognize them as dangerous.
Moderate padding in the preheader is not that.
But putting invisible characters in the subject line, between the letters of a word or inside a link can look like an attempt to trick the filter.
Although it may seem like a good idea for grabbing attention, “empty” email subject lines, or ones with no visible text, are not more effective. They can also look like spam or seem deceptive. Given the current state of security, I wouldn’t use them.
Jose Argudo, CMO of Mailrelay
There are other effects worth knowing about:
- More expensive SMS: almost all of these characters are outside the basic SMS alphabet. Just one switches the message to Unicode and drops it from 160 to 70 characters per SMS.
- Accessibility: some screen readers read these characters as odd pauses or announce them by name. Use them sparingly if you care about accessible email.
- Errors when copying data: a zero-width space accidentally pasted into an email address or a password makes it “not work” for no apparent reason.
They also show up in AI-generated text.
In April 2025, several analyses detected narrow non-breaking spaces (U+202F) in responses from some ChatGPT models.
There was speculation that they were a watermark, something nobody has proven.
How to detect and remove invisible characters
Is some copied text behaving strangely? Paste it into a plain text editor first, such as Notepad, and copy it again.
Many fillers disappear along the way.
If you need to see them, code editors highlight them. Visual Studio Code, for example, highlights invisible Unicode characters by default.
With an email list, pay attention to the addresses that fail when you import them.
They often have a special space at the beginning or end that you can’t see at a glance.
How Mailrelay helps you
The Mailrelay editor has its own field for preview text.
That way, you decide what’s read next to the subject line, not the first paragraph of the email.
You can compare subject lines with an A/B test. And before sending, the editor’s Spam report warns you if anything in the content might cause problems.
The free account lets you send up to 80,000 emails a month to 20,000 contacts, and there’s human support on every plan.
If you also send SMS, remember that invisible text counts as Unicode and changes the number of messages you use.
Check the SMS marketing entry before your first campaign.
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