Got a question about HTML Editor Online Pro? Here are honest answers to the questions people ask most.
What is HTML Editor Online Pro?+
HTML Editor Online Pro is a free, browser-based tool that lets you instantly write, preview, edit, and test HTML code or HTML files — right in your browser, with no download and no account required. It includes a live preview panel, a built-in code editor, a device simulator, screenshot export, an HTML formatter, an HTML diff viewer, and much more — all completely free.
Is HTML Editor Online Pro really free?+
Yes — 100% free, with no strings attached. There are no premium plans, no feature limits, no ads asking you to upgrade, and no subscription fees. Every feature including device simulation, screenshot export, the code editor, and the diff viewer is completely free to use, as many times as you want.
Do I need to sign up or create an account?+
No account, no email, no signup — nothing. You simply open the page and start using the tool immediately. There is no registration process of any kind. HTML Editor Online Pro is designed to be the fastest way to preview HTML, which means zero friction from the moment you arrive.
How do I preview an HTML file online?+
It's simple. Drag and drop your .html file anywhere onto the page, or click the "Open File" button to browse your device. Your HTML file will render instantly in the preview window. Alternatively, click "Paste HTML" to open the code editor and paste your HTML directly. You can also type any URL into the bar at the top to preview a live website inside the tool.
Can I edit HTML and see a live preview at the same time?+
Yes. The built-in code editor and the live preview panel work side by side in real time. As you type or edit HTML in the editor, the preview updates instantly — no need to click a "Run" button or refresh anything. The editor uses CodeMirror, which provides full syntax highlighting, autocomplete, and auto-close tags for a professional editing experience.
Can I simulate how my HTML looks on iPhone or iPad?+
Yes. The device simulator lets you switch between iPhone (375px), iPad (768px), Laptop (1280px), Desktop (1440px), and Full HD (1920px) screen widths. You can also set a completely custom width if your project requires it. This feature is one of the things that sets HTML Editor Online Pro apart from other free HTML preview tools.
Does it support HTML5, CSS3, and JavaScript?+
Absolutely. The preview runs inside a real browser iframe, which means it supports HTML5, CSS3, JavaScript, Web APIs, Flexbox, Grid, animations, and all modern web standards — exactly the way a real browser would render them. There are no limitations or sandboxing that would affect how your code looks or behaves.
Is my HTML code safe? Does it get uploaded anywhere?+
Your code is completely private and never leaves your device. All HTML processing happens locally inside your browser — nothing is sent to any server, nothing is stored, and nothing is shared. You can use HTML Editor Online Pro with full confidence that your code, your files, and your work remain 100% private.
What is the HTML Diff Viewer?+
The HTML Diff Viewer lets you paste two versions of HTML code side by side and instantly see every difference highlighted between them. It's perfect for spotting changes after editing, comparing two templates, reviewing updates from a client, or catching errors introduced during a revision. This is a professional-level feature that most free HTML tools simply do not offer.
Can I use HTML Editor Online Pro offline?+
Yes. HTML Editor Online Pro is a Progressive Web App (PWA), which means you can install it on your phone or computer and use it even without an internet connection. Once installed, it works just like a native app — you can open it from your home screen or desktop, and all core features are available offline.
