How can I Convert HTML to Text in C#?

user_1670022 0
Viewed 129494

I'm looking for C# code to convert an HTML document to plain text.

I'm not looking for simple tag stripping , but something that will output plain text with a reasonable preservation of the original layout.

The output should look like this:

Html2Txt at W3C

I've looked at the HTML Agility Pack, but I don't think that's what I need. Does anyone have any other suggestions?

EDIT: I just download the HTML Agility Pack from CodePlex, and ran the Html2Txt project. What a disappointment (at least the module that does html to text conversion)! All it did was strip the tags, flatten the tables, etc. The output didn't look anything like the Html2Txt @ W3C produced. Too bad that source doesn't seem to be available. I was looking to see if there is a more "canned" solution available.

EDIT 2: Thank you everybody for your suggestions. FlySwat tipped me in the direction i wanted to go. I can use the System.Diagnostics.Process class to run lynx.exe with the "-dump" switch to send the text to standard output, and capture the stdout with ProcessStartInfo.UseShellExecute = false and ProcessStartInfo.RedirectStandardOutput = true. I'll wrap all this in a C# class. This code will be called only occassionly, so i'm not too concerned about spawning a new process vs. doing it in code. Plus, Lynx is FAST!!

text parsing html .net c#
20 Answers

You could use this:

 public static string StripHTML(string HTMLText, bool decode = true)
        {
            Regex reg = new Regex("<[^>]+>", RegexOptions.IgnoreCase);
            var stripped = reg.Replace(HTMLText, "");
            return decode ? HttpUtility.HtmlDecode(stripped) : stripped;
        }

Updated

Thanks for the comments I have updated to improve this function

user_433370
madcolor_139540

What you are looking for is a text-mode DOM renderer that outputs text, much like Lynx or other Text browsers...This is much harder to do than you would expect.

Jonathan_Holland_19650
inspite_317650

The easiest would probably be tag stripping combined with replacement of some tags with text layout elements like dashes for list elements (li) and line breaks for br's and p's. It shouldn't be too hard to extend this to tables.

EricSchaefer_89760

Here is the short sweet answer using HtmlAgilityPack. You can run this in LinqPad.

var html = "<div>..whatever html</div>";
var doc = new HtmlAgilityPack.HtmlDocument();
doc.LoadHtml(html);
var plainText = doc.DocumentNode.InnerText;

I simply use HtmlAgilityPack in any .NET project that needs HTML parsing. It's simple, reliable, and fast.

Update - you are correct that the above removes tags but does not decode the escaped characters. This will do it:

var a = "This &amp; that";
var result = System.Web.HttpUtility.HtmlDecode(a);
result.Dump();

Using the two together you can get the plain text from the HTML.

user_5275160

Another post suggests the HTML agility pack:

This is an agile HTML parser that builds a read/write DOM and supports plain XPATH or XSLT (you actually don't HAVE to understand XPATH nor XSLT to use it, don't worry...). It is a .NET code library that allows you to parse "out of the web" HTML files. The parser is very tolerant with "real world" malformed HTML. The object model is very similar to what proposes System.Xml, but for HTML documents (or streams).

user_516910

I have used Detagger in the past. It does a pretty good job of formatting the HTML as text and is more than just a tag remover.

Brian_Genisio_366870

This function convert "What You See in the browser" to plain text with line breaks. (If you want to see result in the browser just use commented return value)

public string HtmlFileToText(string filePath)
{
    using (var browser = new WebBrowser())
    {
        string text = File.ReadAllText(filePath);
        browser.ScriptErrorsSuppressed = true;
        browser.Navigate("about:blank");
        browser?.Document?.OpenNew(false);
        browser?.Document?.Write(text);
        return browser.Document?.Body?.InnerText;
        //return browser.Document?.Body?.InnerText.Replace(Environment.NewLine, "<br />");
    }   
}
user_57445770
user_848590
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