Embed Playground

Pick a tool, choose a width, height and theme, and watch it run in a frame on a page background you choose. When it looks right, copy the iframe code, a version wrapped in a width-limited box, or a plain link. The code is the same code the Embed button on every tool page gives you.

This is the first part of the Playground. It previews our own tools. Pasting your own HTML, CSS and JavaScript is not in it yet.

What It Does#

The Playground builds the embed address for a tool, loads it in a frame so you can see and use it, and writes out the code to paste into your site. You control the preview width, the starting height, the theme, whether the theme and fullscreen buttons show (Standard) or not (Minimal), and the page colour behind the preview.

It only reads and displays. It does not change the tool and does not send anything you do to us.

How To Use It#

1. Type in the Tool box. The list narrows as you type; use the arrow keys and Enter, or click. Tools that have no page of their own are not listed.
2. Choose a preview width: Phone (375), Tablet (768), Desktop (1024) or Full width, or type your own between 200 and 2000. Swap exchanges width and height.
3. Set the starting height between 240 and 1600 pixels. Once the tool reports its real height, the preview follows it, exactly as a pasted embed does.
4. Pick a Theme and Standard or Minimal. Minimal removes the theme and fullscreen controls. The Run Local Tools badge stays in both.
5. Change the page background to white, grey, dark or your own colour to see how the tool sits on your site. This changes the preview only, never the code.
6. Copy the embed code, the wrapper or the link. Reset Playground puts everything back to the defaults.

For the step-by-step version without a preview, see Embed A Tool.

The Three Code Boxes#

• Embed code: the iframe plus a short script that lets the frame grow to fit the tool. It is identical to what the Embed dialog copies, including the 500 pixel default.
• Responsive wrapper: the same code inside a box with a maximum width. A pasted iframe is always as wide as its container, so this is where a fixed width goes. With Full width selected the box has no fixed width.
• Plain link: an ordinary link to the tool page. It is a link, not an embed.

Worked Example: Real Results#

These are the addresses and code the Playground produced for the Number base converter.

Things That Surprise People#

• The default theme is light, even in dark mode. Choosing Light with visitor switching adds no theme setting to the address, and embeds start light. Pick Follow the visitor’s system if you want them to match.
• A fixed preview width is only a simulation. The real code is always full width of its container. Use the wrapper to limit it.
• The preview height can differ from the box you typed. The tool reports its height and the frame follows it, as it would on your site.
• The badge cannot be turned off. Minimal removes controls only.

Privacy#

Your choices (tool, size, theme, mode and colours) are saved in this browser so they are there when you come back, and Reset Playground deletes them. Nothing you choose is sent to us. The tool itself makes no network requests and loads no outside libraries.

The preview is a normal visit to the tool’s page on this site, shown in a frame, so your browser fetches that page from runlocaltools.online as it would for any page. If your browser blocks storage inside frames or on this site, the Playground still works but will not remember your choices.

Limits#

• It previews tools on this site only. Previewing your own page or your own HTML, CSS and JavaScript is not part of this version.
• The preview shows the tool as it is live today. If a tool changes, an embed on your site changes too.
• Tools without a page of their own cannot be embedded this way and are left out of the list.
• Width is limited to 200 to 2000 pixels and height to 240 to 1600 pixels, the same limits as the Embed dialog.

How We Tested This#

On 9 November 2026 we loaded this tool’s own code in a simulated browser page on a Linux cloud server and ran 312 checks. All passed. The simulation does not fetch real tool pages, so the live preview itself was checked by hand on the site.

Frequently asked questions#

Where to go next#

• Number Base Converter: a small tool that makes a good first embed to try
• Aspect Ratio Calculator: work out a frame size for the width and height you want