Online HTML Editor with Live Preview
Write or paste HTML and CSS, see the result instantly, switch between desktop, tablet and mobile widths, then copy or download index.html. Free, no sign-up, nothing leaves your browser.
- 1. WritePaste or type HTML and CSS. Tab inserts two spaces, Ctrl+Enter runs the code.
- 2. CheckSwitch the preview between desktop, tablet and mobile widths.
- 3. ExportCopy the code, download index.html or open the result in a new tab.
What is this online HTML editor?
The Ideluma HTML Editor is a free online HTML editor that renders your code in a live preview as you type, made for students, marketers and front-end beginners who need to test a snippet without installing anything. Its main difference from other free editors is a preview you can switch between desktop, tablet and mobile widths in one click.
It is a code editor, not a WYSIWYG (what you see is what you get) tool. You write the markup yourself and the browser renders it in the right-hand panel, which is the best way to learn how HTML actually works. Think of it as a lighter alternative to CodePen for quick tests, or as the W3Schools Tryit editor with responsive widths added.
CSS and JavaScript live in the same file, inside <style> and <script> tags, exactly as they would in a real index.html. That makes it an online HTML and CSS editor as much as an HTML one, and what you download is a complete page you can open on any computer.
How to test HTML code online in 4 steps
To test HTML code online here, paste your code on the left, run it, check the preview at the width you need, then copy or download the result. The whole cycle takes seconds and needs no account.
- Paste or type your HTML into the left panel. Tab inserts 2 spaces and the header shows the current line and character count. If you are starting from scratch, pick a starting point from the Templates menu.
- Run the code. With Auto-run switched on, the preview refreshes as you type. Switch it off and press Run or Ctrl+Enter when you want to control the moment.
- Switch the preview width. The Desktop, Tablet and Mobile buttons above the preview show how the page behaves at each viewport, so you can check responsive design without resizing your browser window.
- Copy or download. Copy puts the code on your clipboard, Download saves index.html to your computer, and the arrow button opens the result in a new tab.
Features: live preview, responsive check, export
This free online HTML editor covers the full loop of writing, checking and exporting a page, and every feature works directly in the browser.
- Live preview. The right panel renders the page as you type, with a short delay so the screen does not flicker. It works as an HTML viewer and runner at the same time.
- 3 preview widths. Desktop, Tablet and Mobile buttons switch the preview frame, a feature most free editors do not have.
- Templates. A blank page, a landing hero and a profile card are one click away when you need a starting point.
- Line numbers and counters. The gutter numbers each line and the header counts lines and characters, which helps when you follow a tutorial.
- Keyboard shortcuts. Tab inserts 2 spaces instead of leaving the editor, and Ctrl+Enter runs the code.
- 1-click export. Copy the code, download index.html or open the result in a new tab.
- Free and private. No sign-up, no ads and 0 bytes sent to a server.
Who this HTML editor is for
This editor suits anyone who needs to see an HTML snippet rendered quickly, from complete beginners to professionals checking a fragment away from their main tools.
- Beginners and students. It is a simple HTML editor for beginners: type a tag, see the result, understand the connection. No setup steps stand between you and your first page.
- Marketers and content managers. Check a block of HTML before pasting it into a CMS, a landing page builder or a newsletter tool, and see how it looks on a phone first.
- Front-end developers. Test a piece of markup or a CSS idea in seconds without opening an IDE or creating a new project.
Your code stays in your browser
Everything you type in the Ideluma HTML Editor is processed on your own computer, and nothing is sent to our server. The editor is a client-side tool: the browser renders your markup inside a sandboxed iframe on the same page, which keeps the preview isolated from the rest of the site.
Because there is no account and no storage, your code is not saved anywhere. Refreshing the page starts you over, so download index.html or copy the code before you leave. That is a deliberate trade-off: no saving means no data to protect.
HTML editor, viewer, runner or compiler: what’s the difference?
An HTML editor lets you write and change code, an HTML viewer shows how existing code renders, an HTML runner or tester does both in one window, and an “HTML compiler” is a misnomer because HTML is rendered by the browser, not compiled. This tool covers the first three roles.
HTML editor
What it doesLets you write and edit markup, often with line numbers and shortcuts
When you need itWriting or fixing code
HTML viewer / previewer
What it doesRenders existing HTML so you can see the result
When you need itChecking a file or snippet someone sent you
HTML runner / tester
What it doesCombines editing and rendering in one screen, usually in real time
When you need itLearning, quick experiments, checking responsive behaviour
“HTML compiler”
What it doesA search term, not a real tool: browsers render HTML directly, so there is nothing to compile
When you need itUse an online HTML runner instead
FAQ about the online HTML editor
What is an HTML editor?
An HTML editor is a program or web tool for writing and editing HTML code, usually with helpers such as line numbers, indentation and a preview. Online HTML editors run in the browser, so there is nothing to install. The Ideluma editor adds a live preview and three responsive widths on top of the basics.
What is the difference between an HTML editor and a text editor?
A plain text editor only stores characters, while an HTML editor understands that you are writing a web page and adds helpers such as line numbers, code-friendly indentation and a rendered preview. You can write HTML in Notepad, but you will not see the result until you open the file in a browser. Here both sit side by side.
Is this a WYSIWYG HTML editor?
No, this is a code editor with a live preview, not a WYSIWYG (what you see is what you get) editor. You write the markup yourself and see the rendered result next to it. For learning HTML that is the better approach, because you understand which tag produces which result instead of relying on a visual toolbar.
How do I test HTML code online without installing anything?
Open this page, paste your code into the left panel and the preview on the right renders it immediately. There is no download, sign-up or plugin. When you are done, use Copy to grab the code or Download to save index.html, then open that file in any browser on your computer.
Is my code saved or sent to a server?
No. The editor runs entirely in your browser and sends 0 bytes to our server. Nothing is stored either, so your code disappears when you refresh or close the page. If you want to keep your work, download index.html or copy the code before leaving.
Can I edit CSS and JavaScript here?
Yes, but inside the same HTML file. Put CSS in a <style> block and JavaScript in a <script> block, exactly as you would in a real index.html. There are no separate CSS or JS tabs, which keeps the editor simple and makes the downloaded file work on its own.
How do I open an existing HTML file in the editor?
Open the file in any text editor, copy its content and paste it into the left panel. The preview renders it at once. After your changes, click Download to save a new index.html, or Copy to put the code back into your original file.
Does the HTML editor work on a phone?
Yes. On a phone the code and preview panels stack vertically and the buttons shrink to icons, so the editor stays usable on a small screen. For serious editing a tablet or a computer is more comfortable, and the Mobile preview width lets you check phone layouts from a desktop anyway.
Which HTML editor is best for beginners?
For a first contact with HTML, an online editor with a live preview and no setup is the easiest option, because you see the result of every tag right away. Once you build full projects, move to an IDE such as Visual Studio Code. This editor is meant for the first stage and for quick checks later.
Other Ideluma tools
The HTML editor is one of the free tools on Ideluma. Build tracking links for your campaigns with the UTM Builder, or find a name for a startup or product with the Brand Generator.
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