How to use our I or L Checker
To get started, enter some text into the text-box above.
In the gray box below the text-box you will see your text displayed in an easy to read font with the I's and L's color coded. Also the number one's, zero's and uppercase O's will be color coded as well.
Below the gray box is a key that tells you what color each character corresponds to. The lowercase letter L's will be highlighted in yellow, the uppercase letter I's will be highlighted in blue, the number one's will be highlighted in purple, the uppercase letter O's will be highlighted in orange and the number zero's will be highlighted in green.
This tool isn't just an I or L checker, it also works as an O or 0 checker.
How to manually tell an uppercase "I" apart from a lowercase "L"?
Telling an uppercase "I" apart from a lowercase "L" can be tricky depending on the font.
In a Serif font an uppercase "I" will have a flat line on the top of the "I" and on the bottom of it.
A lowercase "L" will have a curve or flat line at the bottom and a curve or line on the top-left.
A number one (1) is a little easier to tell apart. It usually has a slanted line on the top left and in Serif fonts usually has a flat line on the bottom as well.
In many San-Serif fonts including the font San Francisco, which is the font Apple uses, the lowercase "L" and uppercase "I" are identical.
In this case you can guess which one it is based on the context. Although this may sound obvious, if an uppercase "I" is alone or at the beginning of a sentence or beginning of a name it is most likely an uppercase "I".
But if it is in the middle of a word it is most likely a lowercase "L". In the words "Hello", "Dolphin" or "Jellyfish" it is clear that it is a lowercase "L" in the middle and not an uppercase "I".
If you have trouble determining the difference between the uppercase "I" and lowercase "L" scan the text and see if there are other I's or L's that have a better context surrounding them, and then compare that to the one you are struggling with.
In the event that your text is a password or code with uppercase and lowercase letters scrambled together and the font is San-Serif it will be impossible to tell the difference and you will need to use an "I or L checker" like ours.
The vertical bar (|), also known as the pipe character is also similar to the uppercase I and lowercase L. The way to distinguish it from the others is that it is just a straight vertical line and does not have any other lines or serifs. It also is lower than the other letters, similar to how a "j" or a "y" goes down lower.
How to tell the number 0 apart from the uppercase letter O?
Typically, the uppercase letter "O" is more rounder and wider whereas the number zero is narrower and more oval.
Some fonts will have a slash through the zero as well.
Again, don't forget the context. A zero is more likely to be surrounded by numbers, and an uppercase "O" is more likely to be surrounded by other letters.
What is the difference between a San Serif font and Serif?
Sans Serif fonts do not have lines at the end of letters and appear smoother. In the letter "I" a Serif font appears to have a "hat" and "feet" due to a horizontal line on the top and bottom. In a Sans Serif font, the letter "I" will just be a straight vertical line. Examples of Sans Serif fonts include Arial, Helvetica, Roboto and Calibri.
Serifs have extra lines/extensions on the ends of the letters to add a stylistic flair. A few examples of popular Serif fonts include Times New Roman, Georgia, Baskerville and Garamond.
Serif fonts are frequently used in print such as newspapers, books and magazines due to their more traditional and formal appearance.
Sans Serif fonts are more likely to be used digitally especially on phones due to their more modern appearance.
Many Sans Serif fonts make it impossible to distinguish between certain characters, making an L or I checker tool like ours necessary.
Additional tricky characters
Number 2 and uppercase Z - On the number "2" look for a curved top half whereas the letter "Z" will have straight zig zag lines and the top and bottom horizontal lines will be parallel to each other. However the bottom half of both characters will appear the same.
Number 8 and uppercase B - The uppercase "B" has a flat line on the left side whereas the number "8" is rounded on the left (and both) sides. Also on the number "8" the top circle is usually smaller than the bottom circle.
Uppercase G and number 6 - While both characters have a curved left side, the number "6" has a loop at the bottom that connects and the uppercase "G" doesn't connect. The uppercase "G" has a flat horizontal line in the middle. Another thing to look for is that the uppercase "G" is usually a little wider than the number "6".
Backtick (`) and Single Quote (') - The single quote is more vertical and the backtick is angled more. Single quotes are much more common in written text and the backtick is usually only found in computer programming.
Hyphen (-), En Dash (–), and Em Dash (—) - The hyphen is the shortest of the three, the en dash is a little bit wider and the em dash is the widest. The hyphen is more commonly used especially informally, the en dash is less commonly used, mainly for academic writing and the em dash is used both informally and formally but not nearly as commonly used as the hyphen. None of them have any serifs attached to them. They are completely flat horizontal lines.
Thank you for using our I or L checker!
Hopefully this I or L checker served you well and you are now able to distinguish your L's from your I's. If you need a tool to count the frequency of the L's, I's, 0's, O's or any other character, feel free to use our Character Frequency Counter.