A square can be a bullet, a checkbox-like mark, a diagram node, a mathematical symbol, or nothing more than decoration. A rectangle can serve many of the same roles. That makes it tempting to treat □, ■, and ▭ as one generic box with different styling.
They are not. Unicode encodes an outlined square, a filled square, and an outlined rectangle as separate characters. The distinction survives even when a font makes their size or proportions look a little different from what you expected.
Fill Separates the Squares; Proportion Separates the Rectangle
- □ — U+25A1 WHITE SQUARE, an outlined square.
- ■ — U+25A0 BLACK SQUARE, a filled square.
- ▭ — U+25AD WHITE RECTANGLE, an outlined horizontal rectangle.
Unicode groups these box-like forms with its geometric symbols. The words white and black belong to the character names; a document theme can still draw either one in red, blue, or any other text color.
A U+25A0 BLACK SQUARE can appear orange in a colored heading. U+25A1 remains WHITE SQUARE even if its outline is rendered in dark blue. The name identifies the shape convention, while styling controls the color you actually see.
▭ Is Its Own Character, Not □ Stretched Sideways
▭ U+25AD WHITE RECTANGLE is encoded independently from □. A font draws the glyph, but software does not create U+25AD by taking U+25A1 and applying horizontal scaling.
Its proportions are not fixed to one exact pixel ratio. A rectangle in one typeface may look noticeably long; in another it may be only moderately wider than it is tall. That variation is one reason screenshots can be ambiguous.
Unicode also has ▯ U+25AF WHITE VERTICAL RECTANGLE. Having separate horizontal and vertical rectangle characters makes orientation part of the encoded distinction here, not merely a rotation effect.
There is a filled counterpart as well: ▬ U+25AC BLACK RECTANGLE. Unicode also pairs that idea with ▮ U+25AE BLACK VERTICAL RECTANGLE. Like the square pair, these horizontal and vertical rectangle forms are separate encoded characters rather than one glyph with a fill or rotation switch.
Squares Come in Several Encoded Sizes
The familiar □ and ■ are only part of a larger size family. Unicode includes characters such as ▫ WHITE SMALL SQUARE, ▪ BLACK SMALL SQUARE, ◻ WHITE MEDIUM SQUARE, ◼ BLACK MEDIUM SQUARE, ⬜ WHITE LARGE SQUARE, and ⬛ BLACK LARGE SQUARE.
These are separate characters, not preset font sizes for U+25A1 or U+25A0. In mathematical notation, Unicode notes that size differences among simple shapes can carry meaning, so collapsing every square to one familiar code point is not always harmless.
In a decorative list, the author may simply have chosen the size that looked best. In technical material, though, normalizing every square to one familiar character can remove a distinction the notation was meant to preserve.
A Hollow Square Might Be a Checkbox—or Not a Character at All
Because □ already resembles an unchecked box, people often press it into service in plain-text to-do lists. Unicode also has ☐ U+2610 BALLOT BOX, whose name is much closer to that role. The dedicated comparison of □ WHITE SQUARE and ☐ BALLOT BOX covers that distinction in detail.
A live checkbox in a web form is a different thing again. Browsers render an interactive control with its own checked state; the interface does not have to contain either □ or ☐ as text.
There is one more trap: the little empty box shown when a font cannot display a character. That missing-glyph placeholder—often called a tofu box—is usually a rendering fallback, not evidence that U+25A1 exists in the source text.
■ and the Stop Symbol ⏹ Are Not the Same Character
A filled square looks naturally “stop-like,” so ■ sometimes appears in media controls or instructions. Media notation has its own stop character as well: ⏹ U+23F9 BLACK SQUARE FOR STOP.
The two are encoded separately. A media player may use ⏹, ■, an emoji-style presentation, an SVG icon, or a shape drawn entirely by CSS. Seeing a solid square next to playback controls tells you the intended action more readily than it tells you the code point.
That same caution applies to legend swatches and status markers. BLACK SQUARE is a shape name, not a universal instruction such as “stop,” “error,” or “selected.”
What the Shape Can—and Cannot—Tell You
Fill is a useful first clue: □ is open and ■ is filled. Proportion helps separate ▭ from the squares. After that, font design and UI rendering can blur the evidence quickly.
From an image, fill and proportion are useful clues but not proof. A hollow square, a filled square, and a horizontal rectangle can often be described confidently even when the exact character cannot.
Live text gives you a definitive check: □ is U+25A1, ■ is U+25A0, and ▭ is U+25AD. They may sit comfortably in the same visual family, but none is just a styled version of another.