Detect URLs in text with JavaScript

user_142474 0
Viewed 249003

Does anyone have suggestions for detecting URLs in a set of strings?

arrayOfStrings.forEach(function(string){
  // detect URLs in strings and do something swell,
  // like creating elements with links.
});

Update: I wound up using this regex for link detection… Apparently several years later.

kLINK_DETECTION_REGEX = /(([a-z]+:\/\/)?(([a-z0-9\-]+\.)+([a-z]{2}|aero|arpa|biz|com|coop|edu|gov|info|int|jobs|mil|museum|name|nato|net|org|pro|travel|local|internal))(:[0-9]{1,5})?(\/[a-z0-9_\-\.~]+)*(\/([a-z0-9_\-\.]*)(\?[a-z0-9+_\-\.%=&]*)?)?(#[a-zA-Z0-9!$&'()*+.=-_~:@/?]*)?)(\s+|$)/gi

The full helper (with optional Handlebars support) is at gist #1654670.

url javascript regex
13 Answers

There is existing npm package: url-regex, just install it with yarn add url-regex or npm install url-regex and use as following:

const urlRegex = require('url-regex');

const replaced = 'Find me at http://www.example.com and also at http://stackoverflow.com or at google.com'
  .replace(urlRegex({strict: false}), function(url) {
     return '<a href="' + url + '">' + url + '</a>';
  });
user_17533490 
let str = 'https://example.com is a great site'
str.replace(/(https?:\/\/[^\s]+)/g,"<a href='$1' target='_blank' >$1</a>")

Short Code Big Work!...

Result:-

 <a href="https://example.com" target="_blank" > https://example.com </a>
user_98774160

If you want to detect links with http:// OR without http:// OR ftp OR other possible cases like removing trailing punctuation at the end, take a look at this code.

https://jsfiddle.net/AndrewKang/xtfjn8g3/

A simple way to use that is to use NPM

npm install --save url-knife
user_73445960

Generic Object Oriented Solution

For people like me that use frameworks like angular that don't allow manipulating DOM directly, I created a function that takes a string and returns an array of url/plainText objects that can be used to create any UI representation that you want.

URL regex

For URL matching I used (slightly adapted) h0mayun regex: /(?:(?:https?:\/\/)|(?:www\.))[^\s]+/g

My function also drops punctuation characters from the end of a URL like . and , that I believe more often will be actual punctuation than a legit URL ending (but it could be! This is not rigorous science as other answers explain well) For that I apply the following regex onto matched URLs /^(.+?)([.,?!'"]*)$/.

Typescript code

    export function urlMatcherInText(inputString: string): UrlMatcherResult[] {
        if (! inputString) return [];

        const results: UrlMatcherResult[] = [];

        function addText(text: string) {
            if (! text) return;

            const result = new UrlMatcherResult();
            result.type = 'text';
            result.value = text;
            results.push(result);
        }

        function addUrl(url: string) {
            if (! url) return;

            const result = new UrlMatcherResult();
            result.type = 'url';
            result.value = url;
            results.push(result);
        }

        const findUrlRegex = /(?:(?:https?:\/\/)|(?:www\.))[^\s]+/g;
        const cleanUrlRegex = /^(.+?)([.,?!'"]*)$/;

        let match: RegExpExecArray;
        let indexOfStartOfString = 0;

        do {
            match = findUrlRegex.exec(inputString);

            if (match) {
                const text = inputString.substr(indexOfStartOfString, match.index - indexOfStartOfString);
                addText(text);

                var dirtyUrl = match[0];
                var urlDirtyMatch = cleanUrlRegex.exec(dirtyUrl);
                addUrl(urlDirtyMatch[1]);
                addText(urlDirtyMatch[2]);

                indexOfStartOfString = match.index + dirtyUrl.length;
            }
        }
        while (match);

        const remainingText = inputString.substr(indexOfStartOfString, inputString.length - indexOfStartOfString);
        addText(remainingText);

        return results;
    }

    export class UrlMatcherResult {
        public type: 'url' | 'text'
        public value: string
    }
user_50189620

You can use a regex like this to extract normal url patterns.

(https?:\/\/(?:www\.|(?!www))[a-zA-Z0-9][a-zA-Z0-9-]+[a-zA-Z0-9]\.[^\s]{2,}|www\.[a-zA-Z0-9][a-zA-Z0-9-]+[a-zA-Z0-9]\.[^\s]{2,}|https?:\/\/(?:www\.|(?!www))[a-zA-Z0-9]+\.[^\s]{2,}|www\.[a-zA-Z0-9]+\.[^\s]{2,})

If you need more sophisticated patterns, use a library like this.

https://www.npmjs.com/package/pattern-dreamer

user_73445960
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