What it was designed for
Representing an inline object in a document format that separates text from embedded content. Unicode assigns it to the Specials block and to General Category So, which is Symbol, other.
In practice U+FFFC is a placeholder for an embedded object, not a space.
Does U+FFFC work as invisible text?
Yes, in both name fields and message bodies. Object Replacement Character has the Unicode property White_Space=No, so trim() does not remove it and the regex class \s does not match it.
NFKC leaves it unchanged, so a platform that normalizes input before storing it keeps the exact codepoint you pasted. That combination — surviving both the trim and the normalization — is what makes a character dependable rather than occasionally lucky.
How it compares to the alternatives
Four properties decide which invisible character to use, and they separate these three cleanly. Object Replacement Character is shown against the plain space and against the character most often recommended for blank names.
| Property | U+FFFC | U+0020 | U+3164 |
|---|---|---|---|
| Category | So | Zs | Lo |
| Removed by trim() | No | Yes | No |
| NFKC | stable | stable | → U+1160 |
| Rendered width | Wide | Narrow | Wide |
| UTF-8 bytes | 3 | 1 | 3 |
| Works in a name field | Yes | No | No |
Object Replacement Character matches the reference character on both decisive properties, which is why it works where a space fails.
How to type U+FFFC
To insert U+FFFC, copy it from the button above. Copying is the only method that behaves identically on every operating system and in every application.
Copy and paste
Use the copy button at the top of this page. Paste into the destination field directly. If the field rejects it, paste into a plain-text editor first and copy from there — rich-text editors and some mobile keyboards rewrite pasted content.
In code
Insert it by escape sequence rather than by pasting a character no reviewer can see. A literal invisible character in a source file is unreadable in review and survives copy-paste into places it was never meant to reach.
- JavaScript and TypeScript —
"\uFFFC" - Python —
"\uFFFC" - HTML —
or - CSS
content—"\FFFC" - URL encoding —
%EF%BF%BC
Keyboard entry
Keyboard methods exist and none is reliable across systems. On Linux and in most GTK applications, Ctrl+Shift+U followed by fffc and Enter inserts the character. On macOS, the Unicode Hex Input source acceptsOption plus the four hex digits, and it must be enabled in Keyboard settings first.
Windows Alt codes do not cover this range. The Alt plus numeric-keypad method addresses legacy code pages rather than Unicode codepoints, so it cannot produce U+FFFC. Copying remains the dependable method on every platform.
How many fit in a field
As many as the field's limit allows, because each one counts as a full character. An invisible character is not free — it consumes the same budget as a letter.
It costs 3 bytes in UTF-8, against 1 byte for a plain space. Fields enforce either a character limit or a byte limit, and the two give very different answers. A 20-character gamertag holds 20 of them. A 20-byte field holds 6.
Platforms rarely state which limit they enforce. A field that accepts 20 letters and rejects 20 invisible characters is counting bytes, so divide the stated limit by 3 to find the real ceiling.
Why U+FFFC fails, and what to do
It fails when a field restricts input to an allowlist that excludes its category. Everything else about the character is stable, so a failure almost always traces to that one condition.
The field clears itself after saving. The value was trimmed to an empty string and the platform restored the previous one. Move to a character withWhite_Space=No, which this one already has.
A box or question mark appears. The font has no glyph at U+FFFC, so the renderer drew .notdef. The stored value is correct and only the display is wrong. U+2800 has the widest font coverage of the invisible characters.
The value changes between saving and reloading. The platform normalized it. NFKC leaves Object Replacement Character unchanged, so the cause is a platform-specific substitution rather than normalization.
It works on desktop and fails in a mobile app. The two clients validate separately, and some mobile keyboards strip invisible characters on paste. Paste into a plain-text notes app first, then copy from there.
Where it is used
It is used wherever a field must not be empty but should look empty. Platform behaviour differs enough that each category has its own guide.
- Gaming — in-game names across 9 platforms
- Social media — display names across 10 apps
- Messaging — blank messages across 5 apps
How to find it in existing text
Match it by category rather than by codepoint. The regex\p{So} matches Object Replacement Character and every other character in its category, and it keeps working across Unicode releases.
To confirm whether a specific string contains it, paste the string into the invisible text detector, which lists every codepoint with its category and byte length.