DevToolbox

Format Converters

Convert structured data between YAML, JSON, XML, TOML, CSV, INI, HTML and Markdown — all in your browser.

Structured-data formats each have a job. JSON is the lingua franca of web APIs; YAML is favored for configuration (Kubernetes, CI pipelines) because it is easy to read; TOML is common in application config files; XML still powers many enterprise and office formats; CSV is how spreadsheets talk; INI survives in legacy config; and Markdown is how humans write docs. Converting between them is something every developer does weekly, yet most online converters upload your data to a server. DevToolbox does the opposite: every conversion runs locally with the same battle-tested parsers, so a secrets-laden config file never leaves your machine. Pick a format pair below — each tool keeps the structure intact and reports errors with useful context.

YAML to JSON Converter

YAML is a superset of JSON, so almost every YAML document maps cleanly to JSON. This is the most common config export: take a Kubernetes or CI YAML file and turn it into JSON for an API or a test fixture. Indentation in YAML is significant, and the converter preserves nesting as JSON objects and arrays.

Example

name: dev
type: tool

{ "name": "dev", "type": "tool" }

Does it handle anchors?

Standard YAML anchors and merges are supported via the bundled parser.

JSON to YAML Converter

Turn JSON into clean, human-readable YAML for configuration files. This is handy when an API returns JSON but your tooling expects YAML. The converter produces block-style YAML with correct indentation and quoting.

Example

{ "name": "dev" }

name: dev

Will strings be quoted?

Only when needed to avoid ambiguity; plain scalars are left unquoted.

YAML to CSV Converter

Flatten a list of YAML records into a CSV table. Best when the YAML is an array of objects with the same keys; each key becomes a column. Useful for moving config lists into a spreadsheet.

Example

- name: a
- name: b

name
a
b

What if records differ?

Columns are derived from the union of keys; missing fields become empty cells.

CSV to JSON Converter

Convert spreadsheet rows into an array of JSON objects, one per row, using the header row as keys. The standard bridge between tabular data and JSON APIs.

Example

name,age
dev,3

[ { "name": "dev", "age": "3" } ]

Are numbers kept as numbers?

Values stay strings unless you parse them; this keeps CSV faithful.

JSON to CSV Converter

Serialize an array of flat JSON objects into CSV. Each shared key becomes a column; the result opens directly in Excel or Sheets.

Example

[ { "a": 1 }, { "a": 2 } ]

a
1
2

Does it support nested objects?

Nested values are stringified; flatten first for clean columns.

TOML to JSON Converter

TOML is popular in Rust, Go and Python tooling (pyproject.toml, Cargo.toml). This tool maps TOML tables and arrays into JSON for interchange with web services.

Example

[tool]
name = "dev"

{ "tool": { "name": "dev" } }

Are dates preserved?

TOML local dates are converted to ISO strings.

INI to JSON Converter

Parse classic INI config (sections in [brackets], key = value) into a nested JSON object. Still encountered in PHP and Windows-style config.

Example

[db]
host = localhost

{ "db": { "host": "localhost" } }

How are sections handled?

Each [section] becomes a nested object key.

XML to JSON Converter

Transform XML into JSON for easier processing in JavaScript. Attributes and text nodes are mapped with clear, predictable rules.

Example

<note><to>Dev</to></note>

{ "note": { "to": "Dev" } }

What about attributes?

Attributes are kept as prefixed keys so nothing is lost.

JSON to XML Converter

Serialize JSON into well-formed XML, the reverse of the XML importer. Useful when a legacy endpoint only accepts XML.

Example

{ "to": "Dev" }

<to>Dev</to>

Are arrays supported?

Each array element becomes a repeated node.

JSON to TOML Converter

Emit TOML from JSON for application config files. Tables and arrays-of-tables are written in idiomatic TOML.

Example

{ "name": "dev" }

name = "dev"

Does it produce valid TOML?

Yes, output follows the TOML 1.0 spec.

YAML to TOML Converter

Move YAML configuration into TOML. Convert via a normalized intermediate so nesting and arrays translate correctly.

Example

name: dev

name = "dev"

Why switch YAML to TOML?

TOML is stricter and easier for non-experts to edit by hand.

YAML to INI Converter

Flatten simple YAML into INI sections. Best for shallow configs; deep nesting is collapsed with dotted keys.

Example

db:
  host: localhost

[db]
host = localhost

What about deep nesting?

Deep structures use dotted section keys to stay INI-valid.

TOML to YAML Converter

Convert TOML config into YAML for systems that prefer it. Round-trips through a normalized model for fidelity.

Example

name = "dev"

name: dev

Is it lossless?

For standard TOML types, yes.

XML to CSV Converter

Turn a repeated XML element list into a CSV table. Each child element becomes a row; attributes and text become columns.

Example

<r><n>dev</n></r>

n
dev

When does this work best?

When XML is a flat list of similar records.

CSV to YAML Converter

Build a YAML list of records from CSV, using the header row as keys. Great for seeding config from a spreadsheet.

Example

name
dev

- name: dev

Are headers required?

Yes, the first row defines the keys.

CSV to XML Converter

Wrap CSV rows in XML elements, one node per row, for systems that ingest XML.

Example

name
dev

<row><name>dev</name></row>

What are the element names?

Rows use a generic node; values keep their column names.

XML to YAML Converter

Convert XML documents into YAML for friendlier editing and version control. Attributes are preserved as prefixed keys.

Example

<to>Dev</to>

to: Dev

Why YAML over XML?

YAML diffs cleanly in Git and is easier to read.

JSON to HTML Converter

Render JSON as an HTML definition list or table preview. Handy for quick visualization without a browser extension.

Example

{ "a": 1 }

<dl><dt>a</dt><dd>1</dd></dl>

Is it escaped?

Yes, values are escaped to avoid injection.

HTML to JSON Converter

Extract the text structure of HTML into a JSON tree. Useful for scraping or testing markup parsing.

Example

<p>hi</p>

{ "tag": "p", "text": "hi" }

Does it parse full pages?

It parses the markup you paste; large pages may be truncated for display.

YAML to HTML Converter

Turn YAML data into an HTML preview. Convert via JSON so the structure is normalized first.

Example

name: dev

<dl><dt>name</dt><dd>dev</dd></dl>

When is this useful?

For a quick human-readable view of config data.

HTML to YAML Converter

Serialize an HTML fragment's structure into YAML. The inverse of the YAML-to-HTML tool.

Example

<p>hi</p>

"tag": "p"

What is preserved?

Tag names and text; attributes are included as keys.

TOML to CSV Converter

Flatten a TOML array of tables into CSV. Each table becomes a row, keys become columns.

Example

[[item]]
name="dev"

name
dev

What about scalar tables?

Top-level scalars become a single-row table.

CSV to TOML Converter

Write CSV rows as a TOML array of tables. A clean way to generate config from a spreadsheet.

Example

name
dev

[[item]]
name = "dev"

Are headers required?

Yes, they name the columns.

INI to YAML Converter

Convert INI sections and keys into YAML mappings. A modern replacement for legacy config.

Example

[db]
host=local

db:
  host: local

Are comments kept?

INI comments are dropped during conversion.

Markdown to JSON Converter

Capture Markdown text as a JSON string field for storage or transport. Pair with the JSON-to-Markdown tool for round trips.

Example

# Hi

{ "md": "# Hi" }

Does it parse structure?

It stores the raw text; structural parsing is a separate concern.

JSON to Markdown Converter

Pretty-print a JSON value as a fenced Markdown code block. Ideal for docs and READMEs.

Example

{ "a": 1 }

```
{ "a": 1 }
```

Is it just a code block?

Yes, JSON wrapped in a Markdown fence.