HTML Viewer

HTML Viewer

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What is HTML Viewer

An HTML viewer takes the HTML you paste in and shows the rendered page next to it, so you can see what your markup actually produces instead of reading angle brackets. Type or paste a snippet, import a whole file, or fetch a public URL, and review the live preview with zoom, Inspect, and Mobile / Tablet / Desktop widths.

HTML Viewer on Tools Viewer keeps editing in your browser. Use View for a single HTML editor beside the preview, or switch to Panels when you also need CSS and JavaScript panes. Preview runs in a sandboxed iframe (scripts and forms are allowed inside the frame) so you can try snippets, embeds, and layout fixes without installing an IDE.

When you finish, copy from the editor, download an .html file, or open Preview tab to view the current document in a new browser tab. There is no PDF/PNG/JPG export in this tool — use the dedicated image and PDF converters when you need a snapshot file.

How to use HTML Viewer

  1. Step 1: Add your HTML. Type or paste into the editor, Import a .html / .htm / .txt file, load Sample, or use Fetch URL for a public page. In Panels mode, put CSS in the CSS pane and JavaScript in the JS pane.
  2. Step 2: Choose View or Panels. View keeps one HTML editor next to Live Preview. Panels splits HTML, CSS, and JS so you can tweak styles and scripts while watching the preview update.
  3. Step 3: Preview and inspect. Use Live Preview with zoom, Refresh, and Inspect. Switch Mobile, Tablet, or Desktop widths to check how the layout behaves at common viewport sizes.
  4. Step 4: Copy, download, or open a preview tab. Copy markup from the editor, Download an .html file, or use Preview tab to open the rendered HTML in a new tab while you keep editing here.

HTML Viewer Features

  • Live iframe preview of your HTML
  • View layout (HTML + preview) and Panels layout (HTML, CSS, JS + preview)
  • Import .html / .htm / .txt and optional Fetch URL
  • Sample content, copy, and Download as .html
  • Preview tab for a full-tab render
  • Inspect, zoom, Refresh, and Mobile / Tablet / Desktop preview widths
  • Sandboxed preview iframe for trying scripts and forms in isolation
  • Light / Dark chrome and fullscreen

Common use cases

  • Debugging HTML and CSS: Paste a broken fragment to see whether the issue is in the markup itself or in styles from a larger project.
  • Prototyping UI pieces: Try buttons, cards, or layout blocks in isolation and tweak CSS in Panels mode for instant visual feedback.
  • Checking responsive layouts: Use Mobile / Tablet / Desktop widths to verify media queries without constantly resizing your browser window.
  • Testing small JavaScript snippets: Add script in the JS pane (Panels) and watch DOM behavior in the sandboxed preview.
  • Email or landing HTML checks: Paste strict table-based or inline-styled HTML and confirm it renders before you move it into a campaign tool. For full email client sims, use HTML Email Builder.
  • Validating embed codes: Drop in third-party widgets or iframes and confirm they load in preview before putting them on a production page.
  • Learning by doing: Beginners can combine HTML, CSS, and JS and see results immediately without setting up a local project.
  • Saving a local copy: Download .html when you want a file you can open offline or attach to a ticket.

Examples / supported formats

HTML Viewer works with web markup you edit and preview in the browser:

  • HTML in the editor (paste or type)
  • Import: .html, .htm, .txt
  • Optional public URL via Fetch URL
  • Optional CSS and JavaScript panes in Panels mode
  • Download: .html
  • Preview tab opens the current HTML document in a new browser tab

Pairs well with the rest of the HTML toolbox: tidy indentation in HTML Formatter, check issues with HTML Validate, compress with HTML Minify, or diff two versions in HTML Compare. Need a snapshot file? Use HTML to PNG, HTML to JPG, or HTML to PDF.

FAQ

Is HTML Viewer free?
Yes. Tools Viewer tools are free to use in the browser with no account required.
Do I need to create an account to use HTML Viewer?
No. Open the tool and start working — signup is not required.
Is my content uploaded to your servers?
Pasted or imported content for HTML Viewer is processed in your browser. Tools Viewer does not store it. Optional Fetch URL (when available) retrieves a public page through a short-lived request so you can edit the result locally.
Will it run my JavaScript?
Yes. In Panels mode, JavaScript in the JS pane runs in the sandboxed preview iframe. Standard DOM updates work; the frame is isolated from your main Tools Viewer session cookies.
Can I link to external CSS or JS files?
Yes — use normal link and script tags pointing at public URLs. Your browser still enforces CORS; if the host blocks cross-origin requests, those assets may not load in preview.
How do the mobile and tablet views work?
The Mobile, Tablet, and Desktop controls resize the preview to common widths (for example mobile at 375px) so you can check media queries without resizing the whole browser.
Can I export PDF, PNG, or JPG from HTML Viewer?
Not in HTML Viewer. Download saves .html. For image or PDF snapshots, use the dedicated HTML to PNG, HTML to JPG, or HTML to PDF tools.
Does HTML Viewer validate or diff my markup?
No dedicated Validate or Compare views here. Use HTML Validate or HTML Compare for those jobs.
Do I have to include a full HTML document?
Not for simple tests — fragments often render fine. Include a full document when you need head meta, page-level CSS, or document structure to match production.
What is a good HTML viewer?
A good HTML viewer renders as you edit, supports CSS/JS when you need it, lets you check mobile and tablet widths, and keeps your code in the browser without forcing an account. That is what HTML Viewer on Tools Viewer is built for — free, with Download .html when you want a file.
How do I open an HTML viewer in Chrome?
Chrome does not ship a side-by-side editor and live preview. Open this page in Chrome (or any modern browser), paste or import your HTML, and use Live Preview — nothing to install.