Difference between overflow-wrap and word-break?

Question

What´s the exact difference between overflow-wrap/word-wrap and word-break? And can anybody tell me what´s the better one for breaking very long links? Most people say you should use word-break in combination with overflow-wrap but it doesn't look very logical. I think using overflow-wrap in combination with word-wrap for better cross-browser support is the best method. What do you think?

Transpontine

To any future readers who might be initially confused as to why this was closed as a duplicate question. The CSS Text Module Level 3 states that overflow-wrap and word-wrap should be 100% identical in functionality. Personally, I get the impression that word-wrap should only be used for legacy browser support and that it might be deprecated or dropped in a future version of CSS. – Seigler

To the ones who voted to close this: this is not a duplicate as stated, the question is not the same. The alleged duplicate is about two specific values of the two properties and this question is about the two properties. I really dislike that some people believe to have the right to forbid others answering a question. If you don’t like a question, just don’t read it! – Meathead

@Tyler Crompton You are confusing word-wrap with word-break – Maquis

I agree with Hibou57. This is not a duplicate. It's unfortunate it's closed since it's difficult to find an answer to this question online. – Officialese

@TylerCrompton This question is not about word-wrap. This is about word-break. Closing this as duplicate question doesn't make sense. – Whitehot

@LoneLearner, this was asked over three years ago. What you said has already been stated in the most upvoted comment. Additionally, there is already an accepted answer anyway. Please don't necro questions unnecessarily. – Seigler

@TylerCrompton The accepted answer only quotes another source without really going into a discussion on how they are different and what kind of different behavior word-wrap would produce compared to overflow-wrap. Like the highest voted comment to the answer mentions, "What a non-answer." – Whitehot

@LoneLearner, I agree that I and the other voters improperly closed this question. I also agree that the accepted answer doesn't answer the question. However, this question is over six years old. If you still feel that this question deserves to be reopened, then please cast a reopen vote. If I notice that the question has been reopened, then I will gladly answer it. – Seigler

Answer 1

Quoting from source

• overflow-wrap: The overflow-wrap CSS property is used to specify whether or not the browser may break lines within words in order to prevent overflow when an otherwise unbreakable string is too long to fit in its containing box.

• word-wrap: The word-wrap property was renamed to overflow-wrap in CSS3.

• word-break: The word-break CSS property is used to specify how (or if) to break lines within words

So, you need word-break in combination with word-wrap, which is the right combination.

Yours

Well, yes word-wrap is sufficient, but if the container width is limited, the layout could be messed up. – Yours

OK, I see. I use word-wrap only for links, so the layout doesn´t break. – Transpontine

Found an answer: "The W3 specification that talks about these seem to suggest that word-break: break-all is for requiring a particular behaviour with CJK text, whereas word-wrap: break-word is the more general, non-CJK-aware, behaviour." (#1795609) CJK is a collective term for Chinese, Japanese, and Korean. – Transpontine

Oh. but I thought your question was entirely different. Anyways, glad you found your answers, and I trust i was of help a little bit – Yours

word-wrap is an obsolete Microsoft extension (even if it was implemented as an unprefixed property by most browsers) and has now been replaced by overflow-wrap. MDN merged the two different pages into a single one: developer.mozilla.org/en-US/docs/Web/CSS/overflow-wrap – Awful

@Marzian word-wrap was created by Microsoft but is now part of the spec alongside overflow-wrap. All browsers implement both and they both do the same thing. If you want the largest compatibility use word-wrap or both. – Vial

There is no example here and I don't see how this answer really explains the difference between overflow-wrap and word-break. – Steroid

Please elaborate on this. It's not a clear answer. The way you put it, it seems like word-wrap and word-break are the exact same thing. – Saintsimon

Answer 2

It helps to understand that at this point, word-break: break-word is really an alias for overflow-wrap: anywhere.

word-break: break-word is officially deprecated; see the CSS Text Module Level 3 Working Draft:

For compatibility with legacy content, the word-break property also supports a deprecated break-word keyword. When specified, this has the same effect as word-break: normal and overflow-wrap: anywhere, regardless of the actual value of the overflow-wrap property.

The thing to note here is that word-break: break-word is an alias for overflow-wrap: anywhere, NOT an alias for overflow-wrap: break-word.

(word-break: normal is just the default value for word-break, so you can ignore it unless you're setting a different value for word-break.)

How do overflow-wrap: anywhere and overflow-wrap: break-word differ?

The only difference in the documentation between the two is that overflow-wrap: anywhere DOES "consider soft wrap opportunities introduced by the word break" when it is "calculating min-content intrinsic sizes", while overflow-wrap: break-word does NOT.

I guess widths might be more accurate in some cases if it is considering them?

Frustrated

Answer 3

Here are the exact differences: (based on testing in Chrome v81, and confirming my observations by referencing the spec)

white-space

normal (default): collapses whitespace-chains and line-breaks; adds line-breaks where needed
nowrap: collapses whitespace-chains and line-breaks; doesn't add line-breaks
pre-line: collapses whitespace-chains; adds line-breaks where needed
pre-wrap: no collapsing; adds line-breaks where needed
break-spaces: same as pre-wrap, except with spaces able to trigger line-break-adding
pre: no collapsing; doesn't add line-breaks

Note: If the selected white-space value lists "doesn't add line-breaks", the line-break behavior of the following properties is unable to be applied (ie. ignored).

word-break

normal (default): breaks line at end of last word fitting within container [if one exists], else line left unbroken
break-word: breaks line at end of last word fitting within container [if one exists], else at end of container
break-all: breaks line at end of container [can split a word, even with nearby whitespace]

overflow-wrap (legacy name: word-wrap)

normal (default): breaks line at end of last word fitting within container [if one exists], else line left unbroken
break-word: breaks line at end of last word fitting within container [if one exists], else at end of container [if in non-flex container], else line left unbroken
anywhere: breaks line at end of last word fitting within container [if one exists], else at end of container [so same as word-break: break-word]

Note that for overflow-wrap: break-word (as for any combination that leaves lines too long for the container), the unbroken line can cause a flex container to expand beyond the flex ratio specified (forcing other flex containers to shrink to account for the too-long content).

Nonconformity

based on the fact you said "based on docs" I'm assuming this content is largely copied from somewhere? SO typically frowns on content that is just a pure copy of content elsewhere, but either way you must cite sources when copying content to avoid plagiarism. Also, testing in Chrome is hardly reliable as a source for whether something is compliant with how the spec says it. – Joettejoey

@Joettejoey It's not (even close to) a pure copy of content elsewhere. Most of the behavior descriptions were from my direct testing in Chrome, with the referencing of doc pages just to confirm that the behavior I observed was aligned with the spec, and to be sure I wasn't missing additional behavior. A far cry from plagiarism. (I'll update the note at the top to clarify) – Nonconformity

For a true serious and patient reader who really wants to understand everything, this is the best answer. Thanks so much. – Rufena

Answer 4

overflow-wrap emphasizes how to handle overflow, word-break emphasizes how to break words.

Cobaltous

Answer 5

I tried all the values to better understand how they affect the final result and this is what I got:

overflow-wrap (ex. word-wrap):

/*Set dimensions*/
div {
  height: 200px;
  width: min-content;
  max-width: 9em;
}

/*Set overflow-wrap*/
div#normal { overflow-wrap:normal; }
div#break-word { overflow-wrap:break-word; }
div#anywhere { overflow-wrap:anywhere; }
div#anywhere-wo-mincontent { overflow-wrap:anywhere; width: unset; }

/*Set other*/
body { display: flex; }
div { border: 1px solid; display: inline-block; margin: 30px; }
code { text-decoration: underline; }

  <div id=normal><code>overflow-wrap:normal</code><br>Most words are short & don't need to break. But Antidisestablishmentarianism is long.
  グレートブリテンおよび北アイルランド連合王国という言葉は本当に長い言葉</div>
  <div id=break-word><code>overflow-wrap:break-word</code><br>Most words are short & don't need to break. But Antidisestablishmentarianism is long.
  グレートブリテンおよび北アイルランド連合王国という言葉は本当に長い言葉</div>
  <div id=anywhere><code>overflow-wrap:anywhere</code><br>Most words are short. But Antidisestablishmentarianism is long.
  グレートブリテンおよび北アイルランド連合王国という言葉は本当に長い言葉</div>
  <div id=anywhere-wo-mincontent><code>overflow-wrap:anywhere</code><br>Most words are short & don't need to break. But Antidisestablishmentarianism is long.
  グレートブリテンおよび北アイルランド連合王国という言葉は本当に長い言葉</div>

word-break:

/*Set dimensions*/
div {
  height: 200px;
  width: min-content;
  max-width: 9em;
}

/*Set overflow-wrap*/
div#normal { word-break:normal; }
div#break-all { word-break: break-all; }
div#break-all-wo-mincont { word-break: break-all; width: unset; }
div#keep-all { word-break: keep-all; }
div#break-word { word-break: break-word; }
div#break-word-wo-mincont { word-break: break-word; width: unset; }

/*Set other*/
body { display: flex; }
div { border: 1px solid; display: inline-block; margin: 30px; }
code { text-decoration: underline; }

  <div id=normal><code>word-break:normal</code><br>Most words are short & don't need to break. But Antidisestablishmentarianism is long.
  グレートブリテンおよび北アイルランド連合王国という言葉は本当に長い言葉</div>
  <div id=break-all><code>word-break:break-all</code><br>Most words are short & don't need to break. But Antidisestablishmentarianism is long.
  グレートブリテンおよび北アイルランド連合王国という言葉は本当に長い言葉</div>
  <div id=break-all-wo-mincont><code>word-break:break-all</code><br>Most words are short & don't need to break. But Antidisestablishmentarianism is long.
  グレートブリテンおよび北アイルランド連合王国という言葉は本当に長い言葉</div>
  <div id=keep-all><code>word-break:keep-all</code><br>Most words are short. But Antidisestablishmentarianism is long.
  グレートブリテンおよび北アイルランド連合王国という言葉は本当に長い言葉</div>
  <div id=break-word><code>word-break:break-word</code><br>Most words are short & don't need to break. But Antidisestablishmentarianism is long.
  グレートブリテンおよび北アイルランド連合王国という言葉は本当に長い言葉</div>
  <div id=break-word-wo-mincont><code>word-break:break-word</code><br>Most words are short & don't need to break. But Antidisestablishmentarianism is long.
  グレートブリテンおよび北アイルランド連合王国という言葉は本当に長い言葉</div>

Result:

And I noted for myself that:

• word-break: break-all
  is the most compact option, but you have to be careful because it depends on width: min-content;
• word-break: keep-all
  is the only one that keeps cjk text (and also other alphabets) on the same line. Almost like : normal; but for cjk.
• overflow-wrap: break-word
  would use it on the rare occasions when word-break: break-all is not appropriate, for example for Opera Mini.

Others:

• overflow-wrap: anywhere
  I don't see use cases for. Also it depends on width: min-content;
• word-break: break-word
  deprecated. Also it depends on width: min-content;
• overflow-wrap: normal and word-break: normal
  initial values (defaults)

Comparison of browser support on caniuse.com (2023-01-24):

Headlong