Calculator
What the HTML Validator does
HTML Validator: checks Status and Report from HTML. Example: the sample loaded on the page gives status No obvious tag issues.
Enter HTML and the HTML Validator reports Status and Report. Results refresh instantly, so trying variations costs nothing but a moment.
Spotting a malformed field is far quicker when the structure is laid out clearly. That is usually what brings developers debugging a payload here.
Because it is all local, the tool is as fast as your device and as private as your own notes.
The meaning of each field, the formula in use, and a worked example that starts from the default inputs are all further down.
What do the HTML Validator fields mean?
The HTML Validator uses 1 input. A complete set of starting values is loaded for you, so nothing is required before the first result appears.
| Field | What to enter | Default |
|---|---|---|
| HTML | paste or type any amount of text | <div> <p>Hello</p> </div> |
How does the HTML Validator work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same check.
Nothing is computed until the inputs pass their checks, so you will not get a confident answer built on a typo.
Worked example
These are the values the HTML Validator loads by default, and the result it produces from them. This walkthrough uses the starting values, which means you can follow along without typing anything.
| HTML | <div> <p>Hello</p> </div> |
|---|
| Status | No obvious tag issues |
|---|---|
| Report | Basic tag nesting looks fine. For full HTML5 validation use the W3C Nu Html Checker. |
How to use it
- Paste your content into HTML.
- Because it recalculates as you type, you can dial a value in rather than guessing and re-running.
- You get Status and Report back.
- Share the link rather than a screenshot. It carries the values with it.
What this tool does not do
- Output follows the common convention for this format; a specific toolchain may have its own house style.
- Processing happens in your browser, so very large inputs are bounded by available memory.
- Nothing is saved between visits, so keep your own record of anything you need again.
Frequently asked questions
Just HTML. Each field is pre-filled with a sensible default, meaning you can explore the calculation before committing to real figures.
With the values loaded when the page opens, status comes out as No obvious tag issues. Change a value and the number is recomputed on the spot.
Nothing is logged. The tool is client-side code; your data stays where you entered it.
It is free to use, with no premium tier holding back the useful parts.
The output is deterministic. The same inputs always give the same answer, and the method is documented above so you can check it.