JSON to HTML Converter
Turn JSON into clean, embeddable HTML: a flat table, nested <ul>/<li> lists, a <dl>/<dt>/<dd> description list, or semantic markup that maps objects to description lists and arrays to ordered lists. Every value is HTML-escaped, the result renders in a sandboxed preview next to its source, and you can copy the markup or download a standalone page.
Input JSON Data
An array of objects becomes rows and columns; a single object becomes a key/value table.
Elements get classes such as j2h-table and j2h-key.
Load a sample
HTML Output
Paste JSON to see the rendered HTML and its source
About JSON to HTML Converter
A JSON to HTML converter that produces markup you can paste straight into a page. Four output structures are available: a table (an array of objects becomes rows and columns, a single object becomes a two-column key/value table), nested unordered lists, a description list built from <dl>, <dt> and <dd>, and a semantic mode that maps objects to description lists and arrays to ordered lists. Nested objects can either be flattened into dot-notation columns or rendered as sub-tables. Every key and every string value is escaped for &, <, >, " and ', so markup inside the data becomes visible text rather than live HTML, and the rendered result is shown in a fully sandboxed iframe next to its source code.
Why use a JSON to HTML Converter?
HTML is the format that renders identically in a CMS, a static-site build, an email template, a wiki page and a print stylesheet, with no JavaScript and no fetch at view time. Converting a small JSON payload once, at authoring time, removes a runtime dependency. Doing it by hand is where the bugs come from: forgetting to escape a value, producing a zero-column table from an array of strings, or crashing on a key literally named hasOwnProperty. This converter handles each of those cases explicitly and tells you what it did — which columns it derived, how nested objects were treated, and why an array of scalars became a single-column table.
Who is it for?
Technical writers and developers embedding API examples or reference tables in documentation, content managers pasting structured data into a CMS, static-site authors (Hugo, Jekyll, Astro, MDX) who want plain markup instead of a client-side renderer, and anyone who needs to turn a one-off JSON export into something a non-technical colleague can read.
How to use the tool
Paste your JSON into the input box, or switch to 'Load from URL' or 'Upload File' to bring in a .json file
Pick an output structure: Table, Nested list (ul/li), Description list (dl/dt/dd), or Semantic (dl for objects, ol for arrays)
In table mode, decide how nested objects are handled — leave 'Render nested objects as sub-tables' off for dot-notation columns such as stock.warehouse, or switch it on to keep the hierarchy
Set a CSS class prefix so the markup carries classes such as j2h-table and j2h-key, or clear the field to emit no class attributes at all
Toggle 'Include a minimal <style> block' depending on whether the target page already has its own styling
Check the Preview tab to see how the markup renders — it is displayed inside a sandboxed iframe, so nothing in your data can execute
Switch to the Code tab to read the generated source, and read the notes under it for how columns were derived
Copy the HTML for pasting into a page, or use Download .html to save a complete standalone document
Frequently Asked Questions
How do I convert JSON to HTML online?
Paste the JSON, upload a .json file, or load a public URL, then choose one of four output structures: a table, nested <ul>/<li> lists, a <dl>/<dt>/<dd> description list, or semantic markup that uses <dl> for objects and <ol> for arrays. The result appears immediately in two tabs — Preview shows it rendered, Code shows the source. Adjust the CSS class prefix and the optional <style> block to match the page you are embedding into, then copy the markup or download a complete standalone HTML document. Everything runs in your browser.
Which output structure should I choose?
Table is right for tabular data — an array of objects with the same keys, such as an API collection or a CSV-shaped export. Nested list keeps deep hierarchies readable when rows would be mostly empty. Description list is the accessible choice for a single record's key/value pairs, which is exactly what <dl>, <dt> and <dd> were designed for. Semantic mode combines the two rules — objects become description lists, arrays become ordered lists — and is the closest one-to-one mapping of the JSON data model onto HTML elements, so it survives deeply mixed structures without flattening anything.
Is my JSON data sent to a server when I convert?
No. Parsing, conversion and preview rendering all run in your browser via JavaScript — the JSON never reaches a Toolsana server and is never logged. Verify it in DevTools' Network tab: typing and converting produce zero requests. The one exception is 'Load from URL', where your browser fetches the address you typed; that request goes directly from your machine to the host you named, and it only works if that host sends a permissive Access-Control-Allow-Origin header. For anything sensitive, download the file first and use Upload File.
How are special characters and embedded markup handled?
Every key and every string value is escaped for all five HTML-unsafe characters: & becomes &, < becomes <, > becomes >, " becomes " and ' becomes '. Escaping the quotes matters because it makes the output safe in attribute position too, not only in text. A value of "<script>alert(1)</script>" therefore renders as visible text, not as executable script. The Preview tab adds a second layer: it renders inside an iframe with an empty sandbox attribute, so the document has no scripting and an opaque origin even if you later edit the markup by hand.
What happens to nested objects and arrays inside a table?
By default nested objects are flattened into dot-notation columns: {"stock":{"warehouse":12}} becomes a column named stock.warehouse. Arrays of scalars are joined with commas in one cell; arrays of objects are flattened by index, giving columns like items[0].id. Switch on 'Render nested objects as sub-tables' to keep the hierarchy instead — each nested object or array of objects becomes a small table inside its cell. Rows with different keys are handled by taking the union of all keys, so a missing field simply leaves an empty cell rather than shifting the columns.
Why does an array of strings produce a single 'value' column?
Because there are no keys to turn into column headings. ["alpha","beta","gamma"] has three rows and no field names, so the converter emits one column called value rather than a table with zero columns and a misleading row count. The same rule applies to arrays that mix objects and scalars. If a list reads better as a list, switch the output structure to Nested list or Semantic — an array of scalars then becomes a plain <ul> or <ol>, which is usually the better markup for that shape of data anyway. An array of empty objects such as [{},{}] has no keys at all, so it is rejected with the message "No columns found — the input has no keys to convert" instead of rendering an empty table.
Can I style the output to match my site?
Yes, in two ways. The CSS class prefix field controls the class names on every element — with the default prefix you get j2h-table, j2h-th, j2h-td, j2h-key, j2h-dl, j2h-null and so on, so you can target them from your own stylesheet. Clear the field and the markup is emitted with no class attributes at all, which is what you want when the destination already styles bare <table> and <dl> elements. The 'Include a minimal <style> block' toggle adds a small self-contained stylesheet for a quick standalone page; switch it off when the host page owns the styling.
How much data can I convert at once?
Input is capped at 2 MB. That is a browser-layout limit rather than a parsing one: a <table> with thousands of rows is slow to lay out, painful to scroll and bloats the page it is embedded in. In practice, keep embedded tables under a few hundred rows and paginate or virtualise anything larger on the server. For spreadsheet workflows, [JSON to CSV](/tools/json-to-csv/) is the better target format, and [JSON Formatter](/tools/json-formatter/) or [JSON Validator](/tools/json-validator/) will help you clean up a payload before converting it.
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