Why does my HTML file show code instead of a web page?

Almost always one of five things: the file is not really named .html (often report.html.txt with extensions hidden), a server is sending it as Content-Type text/plain, you are looking at it in a viewer that only displays source, the markup itself is escaped as <div>, or the content is wrapped in a code block. The address bar and the browser's network panel tell them apart in under a minute.

How do I check the real file extension?

On Windows, turn on File name extensions in File Explorer's View menu; on macOS, Get Info shows the full name. A file saved from a chat or an email is often report.html.txt, which every browser treats as text.

How do I check what Content-Type the server sends?

Open DevTools, go to the Network tab, reload, click the document request and read the Content-Type response header. It must be text/html. text/plain or application/octet-stream means the host is misconfigured, and no change to the file will fix it.

The page shows <div> literally — what happened?

The markup was HTML-escaped somewhere along the way, usually by a tool that pasted it into a template or a JSON field. Unescape it once and it renders; the free HTML escape tool does this in the browser.

What is the fastest way to just see the page?

Paste the markup into an HTML viewer that renders it. If other people need to see it too, publish it to a link served as text/html so nobody has to fix their own copy.

The browser shows tags, not the page

You open the report and get a wall of <div class="…"> in a monospace font. The file is fine — something between the file and your eyes is treating it as text. There are five usual suspects, and they take about a minute to rule out.

Tell them apart

What you see	Likely cause
Address bar ends in `.txt`, or the icon is a text file	Wrong extension
Served from a URL; DevTools shows `Content-Type: text/plain`	Server sends the wrong type
You're in GitHub, a Drive preview, an email or an IDE	A source-only viewer
Text reads `<div>` or `<div>` with no styling at all	Escaped markup
Tags inside a grey box, or after a stray line of text	It's wrapped in something

1. The file isn't really HTML

Files saved from chats, emails and "Save as" dialogs often end up as report.html.txt, and both Windows and macOS hide the last extension by default. Browsers pick a renderer by extension for local files, so the page opens as plain text.

Fix: show extensions (File Explorer → View → File name extensions; Finder → Get Info), rename to .html, reopen.

2. The server says it's text

Over HTTP the extension doesn't matter — the Content-Type header does. DevTools → Network → reload → click the document → Response Headers. If it says text/plain, the browser is doing exactly what it was told. application/octet-stream usually downloads instead of displaying — that variant is covered in S3 downloads instead of rendering.

A few hosts do this deliberately. Raw file endpoints on code hosts serve .html as text/plain so user uploads can't run scripts on their domain, which is why a raw link to a report never renders — htmlpreview alternatives explains the workaround people reach for and why it breaks.

Fix: set the object's content type to text/html; charset=utf-8 on a host you control, or publish somewhere that serves it correctly.

3. You're in a viewer that only shows source

GitHub's file view, Google Drive's preview, most email clients, Slack's snippet view, and every code editor show HTML as code on purpose — rendering uploaded HTML would execute someone else's scripts inside their product. See Slack won't preview HTML and share an HTML file from Google Drive.

Fix: open it in an actual browser tab, or paste it into the free HTML viewer, which renders it in a sandbox.

4. The markup is escaped

If the page shows <table>, or shows <table> as visible text with no layout at all, the markup was HTML-escaped once too often — usually by a template, a CMS field or a JSON serializer that didn't know it was holding HTML.

Fix: unescape it once. The HTML escape / unescape tool does this in the browser; then check the result renders.

5. It's wrapped in something

Two common versions:

A Markdown code fence. Output copied from a chat often keeps the ```html fence. Anything rendering that as Markdown shows a code block. Delete the fence lines.
Text before <!DOCTYPE html>. A log line or a BOM-mangled header ahead of the document can push some viewers into treating the whole thing as text. Make <!DOCTYPE html> the first thing in the file.

So nobody else hits this

Every one of these is a problem the reader has to solve on their own copy. Publishing the report to a link that is served as text/html, over HTTPS, with its assets alongside, removes all five at once — and readers can comment on the page instead of messaging you that "it's just showing code".

Publish an HTML file to a link →