I had heard some debate on this topic, and I had always learned to use two spaces after a period. But it would seem there is an argument against it.

However, I do not understand what the issue is against this practice.

  • 5
    Sorry, exact dupe! english.stackexchange.com/questions/2544/…
    – Trufa
    Commented Feb 4, 2011 at 23:18
  • 1
    Note that the iPhone gives you a period automatically after you've typed two spaces. So there's Steve's answer.
    – user909
    Commented Feb 4, 2011 at 23:25
  • 4
    @Oliver - when you type two spaces on an iOS device, it automatically turns into a period + one space.
    – Dori
    Commented Feb 5, 2011 at 0:44
  • 5
    This is a misleading question, because the question of how many spaces you type in your input is different from how wide the space looks in the output (e.g. in HTML), and if for the latter you are forced to choose between "one space" and "two spaces" (whatever that means), you have more serious problems with your typesetting system that you need to worry about first. Commented Feb 5, 2011 at 6:37
  • 3
    HTML shows only one space per set so you can format your code, not so you are grammatically correct - you use   if you want more spaces :)
    – Jane Panda
    Commented Feb 5, 2011 at 14:52

16 Answers 16


In short, this is a disagreement based on technological generations.

When everyone was handwriting things, there was no issue - the space after a period was however large the writer thought looked good.

But with the first generation of typewriters, a decision had to be made. These were monospace typewriters, and with fixed spacing it was considered that two spaces after the period set it apart and made it clearer when the sentence ended, distinguishing more clearly from a comma.

With late-70's proportional spacing typewriters, and even more with the advent of word processors, the system became intelligent enough to adjust the space depending on the letters on either side, a process known as kerning in the typographical world. This allowed the space after the comma and the space after the period to be clearly distinguished even if they were both typed as a single space.

Thus, the debate: those of us who grew up with typewriters were taught "always use two spaces after a period," while younger folks who grew up with word processors were taught (frequently by Microsoft's grammar checker) to use a single space.

My answer? I try to use a single space in documents, but two spaces when I'm using a monospace font (such as comments in computer code). And the entry field on this site, which displays monospace while I type but publishes as proportional spacing, is really confusing me. :)

  • 5
    Perfect answer. Commented Feb 4, 2011 at 19:38
  • 2
    tldr: It's a matter of preference. +1
    – StrixVaria
    Commented Feb 4, 2011 at 20:17
  • 17
    "younger folks who grew up with word processors were taught to use a single space." As an illustration, I'm 26 and just now, reading this question, I have for the first time heard about the issue. I honestly did not know there are people who double-space after dots on purpose. Commented Feb 4, 2011 at 23:55
  • 2
    Two is wrong. Why it was once OK is an interesting piece of history, nothing more.
    – MGOwen
    Commented Feb 7, 2011 at 3:26
  • 2
    A minor historical nitpick/omission: Moveable type standards in America, France, and a few other places, called for em-spacing between sentences. When manual typewriters were existed, there was only a single space, so a double space was used to emulate em-spacing. (read more)
    – Flimzy
    Commented Jun 24, 2015 at 22:24

Very compelling answer to this question on Slate last month. One space is correct, two is wrong. It's not a matter of preference. Two is wrong.

Every modern typographer agrees on the one-space rule. It's one of the canonical rules of the profession, in the same way that waiters know that the salad fork goes to the left of the dinner fork and fashion designers know to put men's shirt buttons on the right and women's on the left. Every major style guide—including the Modern Language Association Style Manual and the Chicago Manual of Style—prescribes a single space after a period. (The Publications Manual of the American Psychological Association, used widely in the social sciences, allows for two spaces in draft manuscripts but recommends one space in published work.) Most ordinary people would know the one-space rule, too, if it weren't for a quirk of history. In the middle of the last century, a now-outmoded technology—the manual typewriter—invaded the American workplace. To accommodate that machine's shortcomings, everyone began to type wrong. And even though we no longer use typewriters, we all still type like we do.

  • 7
    Yes, this is correct: it is not a matter of preference! Amen. Commented Feb 5, 2011 at 0:29
  • 10
    The article is not compelling because it conflates what you should type with how it should be typeset. Much modern typography is done with TeX, which--by default--uses wider, stretchier spaces between sentences than it does between words. We can blame the horrific plague of WYSIWYG tools for the confusion. Commented Feb 10, 2011 at 15:57

As others have mentioned, there's no grammatical reason for two spaces, it's purely a mechanical issue. Since the mechanical context that led to the double-spaces (the typewriter) is pretty much gone, the practice of double-spaces should be gone, too.

  • 2
    I like the visual distinction between sentences it provides. It's like having mini-paragraph breaks. Commented Feb 4, 2011 at 21:40
  • According to this screenwriter, actors do a better job sight-reading scripts that have wider spaces between sentences, suggesting that the visual breaks may be important to comprehension. johnaugust.com/archives/2005/… Commented Feb 11, 2011 at 13:54
  • 1
    Then why am I still typing on a dang qwerty keyboard. On my phone too no less.
    – joshperry
    Commented Feb 11, 2011 at 23:13

I know there is tons of disagreement out there, but I have known several people voice their frustration when they see double spaces after periods — I'm no different. It's the 21st century. We don't have typewriters anymore. We have word processors.

One space after the period gets the point across. Two spaces after the period feels, to me, somewhat like adding an exclamation point after every sentence! Completely unnecessary. It sticks out like a sore thumb. One space looks more natural to the eye because we have now grown accustomed to it.

If you want to use two spaces, though, then use two. Just be consistent throughout the piece.


As Yossi Farjoun pointed out on the english.stackexchange incarnation of this question, part of the controversy here comes from a false dichotomy.  There are really two separate questions involved: one of aesthetics, one of implementation.

  1. Should text be set with a wider space between sentences?  (‘Wider’ doesn’t have to mean ‘exactly double’, of course.)

  2. Should you, when typing, type two spaces at the end of a sentence?

The answer to 1 is debatable: it’s a matter of taste and convention, and varies between publications, between genres, between countries, between languages, and over time.  The current consensus in English, in most genres, is no.  However, there are significant exceptions: Donald Knuth favoured wider inter-sentence spacing, so in communities (eg mathematics, academic CS) where TeX, LaTeX etc. are popular, readers are generally accustomed to it.

The answer to 2 then depends on how your text will be transmitted to the reader.  As html?  Then typing a double space will do nothing: if you really want a wider space, you’ll have to throw in a  .  Via (La)TeX?  If you like wide spacing, do nothing — so does TeX.  If you don’t like that, you’ll have to say so in your document options.  This question has as many answers as there are word processors, markup languages, etc. out there; but this is now a matter of practicality, not of convention or aesthetics.

  • 1
    This is exactly correct. Commented Sep 18, 2015 at 18:57
  • Is this a subliminal message to use two spaces / a wide space between sentences? Because the answer itself does that. Unlike the other answers to this question.
    – Bill Keese
    Commented Oct 15, 2020 at 12:19

The rule is not "two spaces after a period;" it's "two spaces at the end of a sentence." You will notice that the preceding sentence does not end with a period -- nor does this one!

Use two if your text will likely be displayed in a monospace font, such as in e-mail (true e-mail is plain text), a .txt file, source code, or on USENET. It does make it more readable.

Since most people these days do not send true e-mail, write .txt files, or even know what USENET is, that leaves source code. Therefore, if you are not a programmer, use one space.

  • 2
    I'm going to good-naturedly nitpick on this old post: "true email" is not necessarily plain text, it's just ASCII coded content; the content-type header specifies how the ASCII characters should be interpreted and displayed (e.g., as plaintext, as HTML, as something else). Also, plaintext in no way mandates that the characters will be monospaced: that may be typical behavior, but there's no reason plaintext can't be displayed in any font you want, including fonts where different characters are different sizes. Commented Jan 16, 2013 at 15:16
  • 2
    You whippersnappers and your fancy "fonts"!
    – kindall
    Commented Jan 16, 2013 at 16:01

This sounds like the equivalent of the "tabs versus spaces" fight that programmers have.

In the end, if you are being held up by the number of spaces after a period, then I'd just quit writing, because you'll never get past that first sentence.

Or take the e e cummings approach. Screw punctuation entirely.

  • 4
    Tabs make smaller files... uh oh, I'm starting a debate ;)
    – user887
    Commented Feb 4, 2011 at 21:14

When writing for publication, professional or otherwise, this is not a matter of preference. Your best bet is to consult a style guide.

I use The Chicago Manual of Style. I believe most style guides call for one space. I grew up using two spaces, but thanks to Microsoft Word's grammar and style checking, it automatically corrects when I mess up and try to put in two spaces.

If you're not writing for publication, then it is a matter of preference and no one can give you a right or wrong answer.

UPDATE: Since one of the other answers references an online article, I figured I would do the same. See Grammar Girl's brief, informative, and rantless post, "How Many Spaces After A Period?". She also says to use one space. However, she also says this:

Although how many spaces you use is ultimately a style choice, using one space is by far the most widely accepted and logical style. The Chicago Manual of Style (1), the AP Stylebook (2), and the Modern Language Association (3) all recommend using one space after a period at the end of a sentence. (emphasis mine)

If you plan on publishing, one space is your best bet. If in doubt, find which style guide your market adheres to and go with that.


The problem is the tools. When it comes to fine points of typography, WYSIWYG is the wrong way to do it.

Typing and most editing should probably be done with monospace fonts. Reading should be done with beautifully typeset proportional fonts. (See Joel Spolsky's UI book.)

Details like how much wider an inter-sentence space should be than an interword space (if at all) should be a reader choice in any electronic format (e.g., ebooks, websites, etc.), and a book designer choice in hardcopy. Writers should be able to type any number of spaces between sentences. It's the tools' job to accommodate everyone, but most of them don't because they've been tainted by the mistaken notion that WYSIWYG is a good thing.

There are situations where ambiguity can creep in. Consider:

"Run!" I screamed.
"Run!"  I screamed.

This first line is a single sentence. The second is two. They mean slightly different things. Without a difference in spacing distances, this distinction is lost. Admittedly, this is contrived, and many would consider the first line as an example of bad writing.


Agreed. The basic premise of two spaces is now an outmoded idea, however there are many people that still write like this, and many that still teach using two spaces. Most of the time this is simply due to the way that people were originally taught to format typed text, they teach it the way they were taught.

I have a co-worker who is twenty-two years old, and doesn't use a typewriter, but he uses two spaces at the end of every sentence because he was taught that it is the appropriate format. I suspect that this practice will be around for a long time to come, even though it is no longer necessary.


When your text is displayed as an HTML document (web pages, etc.), any extra spaces are automatically collapsed into one space, even if you are using a monospace font.

When your text is displayed (almost) anywhere else in the modern world, single spaces are sufficient in most cases, but you also have the freedom to use a double space to specifically distinguish two statements from one another. Consider your medium, choose your weapon, convey your message.


Helping my 11 yr old son with a project last night, I noticed he was two-spacing it. He just wrapped up a semester of typing at school, I'm pissed at his keyboard teacher because now I'm gonna have to break him of this habit.

I can't believe anyone would teach that in today's world.

  • This is not an answer to the question. It's a rant. Commented Sep 18, 2015 at 18:58
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    Indeed. I find I am unable to recall my state of mind or motivation from 1:30am four-and-half a years ago in regards to this answer. Maybe it's the illegal drugs I took as a young man that cloud my memory, or perhaps it's the prescription drugs I take now. Honestly, they do leave me a little dizzy and, some might say, addled most days. Maybe I'm just old. I certainly do have a solid grip on SE rules and etiquette now, and wouldn't harbor even the thought of such a transgression, but back then, in the heady early days of 2011 - who can say what was in my mind or, dare I contemplate it, my soul?
    – Yardboy
    Commented Sep 24, 2015 at 16:16

I'm an old school web developer (grew up with typewriters), and I sometimes do slip and put a double space in the code. The nice thing is that the browsers take it out for me.

Unless you intentionally encode the double space like so "  ". And who's gonna do that!? :)


One more perspective on the matter was addressed by XKCD.

enter image description here


You may also be interested in the following article: Double Spacing After Periods

  • Oh the irony! The HTML in that article forces wider spaces after colons (another contentious typing conundrum), and it does it the wrong way. When the line break happens after a colon, the next line is indented by one space. I'm supposed to take typing/typesetting advice from this so-called design site? Ha! ;-) Commented Feb 12, 2011 at 18:01

The catty answers from unpublished writers amuse me. I double-space after periods, not because I'm old enough to use a type writer but because that's how I was taught. Double-spacing and monospace fonts absolutely make initial editing much easier. For my final edit, I prefer to make a faux galley to check how well the flow works when it is typeset as it will be as a book. When I turn it in, I only take out the spaces if I'm really pushing 400 pages and it buys me a page or two. (In my genre, publishers get really unhappy when you go over the magic 100k mark.) I've published 6 books with a major NY publisher and never had an editor comment on spacing after a period. The book gets typeset anyway. It's a non-issue.

  • Adding double spaces after a full point is redundancy left over from manual typewriter days. When preparing text for publishing all those double spaces have to be removed. In my early days in the publishing industry that person was often me! They're not needed, all you're doing is creating work for someone else, work someone has to pay for. Don't use them. Commented Dec 15, 2012 at 13:44
  • Can you elucidate the reasons publishers may or may not care about this rule that modern writers are taught is a relic of a bygone age.
    – tylerharms
    Commented Dec 19, 2012 at 20:41

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