Vollstaendiger Dateiformat-Konvertierungsleitfaden

Free CSV · XML · JSON · HTML · Markdown No signup · No data stored · Works offline

Tools in diesem Leitfaden

CSV Formatter & Validator
Format, validate and preview CSV data
CSV to JSON Converter
Parse CSV files to JSON objects
JSON to CSV Converter
Export JSON arrays as spreadsheets
XML Formatter & Validator
Format and validate XML documents
XML to JSON Converter
Convert XML attributes and elements to JSON
JSON to XML Converter
Convert JSON to well-formed XML
HTML to Markdown Converter
Migrate HTML content to Markdown
JSON Formatter & Validator
Format, validate and minify JSON
Last updated: March 2026  ·  v1.0
Quick Answer
How do you convert between CSV, XML, JSON, HTML and Markdown?

Each format conversion has different rules and edge cases. The 5 most important things to know:

  1. CSV to JSON: first row becomes keys; use RFC 4180 quoting for commas inside fields.
  2. XML to JSON: attributes map to @key; repeated sibling tags become JSON arrays.
  3. JSON to CSV: nested objects must be flattened using dot notation (e.g. address.city).
  4. HTML to Markdown: tables, bold, links and headings convert cleanly; custom CSS and colspan do not.
  5. All conversions on this site run entirely in your browser — no data is uploaded to any server.

Data lives in many formats simultaneously. Your database exports CSV, your legacy API returns XML, your frontend expects JSON, and your documentation platform needs Markdown. Moving data between these formats without errors requires understanding each format's rules and where they differ.

CSV to JSON: handling headers, types, and nested data

CSV (Comma-Separated Values) is deceptively simple, but real-world CSV files come with complications that trip up naive parsers.

Header detection: Most CSV files have a header row. Our CSV to JSON Converter treats the first row as keys for the resulting JSON objects. If your file lacks headers, add them before converting.

Type inference: CSV has no type system — every value is a string. A good converter infers types: 42 becomes a JSON number, true becomes a boolean. Our converter applies smart type inference while letting you override when needed.

Quoting and delimiters: Fields containing commas must be quoted. Fields containing quotes must escape them by doubling. RFC 4180 defines these rules. Tab-separated (TSV), semicolon-separated, and pipe-separated variants also exist — our converter auto-detects the delimiter.

XML to JSON: attributes, arrays, and namespaces

XML and JSON represent the same concepts differently. Understanding the mapping rules prevents data loss during conversion.

Attributes vs child elements: XML attributes have no direct JSON equivalent. The standard approach maps them to keys prefixed with @: {"@id": "42"}. Our XML to JSON Converter follows this convention.

Array detection: Multiple sibling elements with the same tag name are implicitly an array. Our converter detects this automatically.

Namespaces: XML namespaces are common in SOAP APIs and enterprise XML. The prefix becomes part of the key name in JSON.

Text content with attributes: An XML element with both text content and attributes maps to a special #text key for the text content.

JSON to CSV: flattening nested objects

Converting JSON to CSV requires making a two-dimensional table out of potentially multi-dimensional data.

Simple arrays: A JSON array of flat objects converts directly to CSV. Each object becomes a row, each unique key becomes a column.

Nested objects: {"address": {"city": "London"}} must be flattened. The standard approach uses dot notation: address.city becomes a column header. Our JSON to CSV Converter handles this with the Flatten nested option.

Arrays within objects: {"tags": ["js", "python"]} has no clean CSV representation. Options include joining values with a separator or using a separate CSV for the array.

HTML to Markdown: migrating content

Converting HTML to Markdown is common when migrating content between platforms — from a CMS to a static site generator, from a web scrape to a documentation tool.

What converts cleanly: Headings, paragraphs, bold/italic, inline code, code blocks, blockquotes, lists, links, and images all have direct Markdown equivalents.

What loses fidelity: Custom CSS classes, complex table layouts, nested lists deeper than two levels, and any semantic HTML that Markdown has no syntax for.

Tables: Standard HTML tables convert to GitHub Flavored Markdown (GFM) table syntax. Complex tables with merged cells cannot be represented in Markdown. Our HTML to Markdown Converter handles standard tables and normalises whitespace output.

Häufig gestellte Fragen zur Datenkonvertierung

Wie konvertiere ich ein CSV mit 100.000 Zeilen in JSON?

Verwenden Sie unseren CSV-zu-JSON-Konverter — er verarbeitet Dateien clientseitig in Ihrem Browser ohne serverseitige Größenbeschränkung beim Upload. Für Dateien größer als ~50 MB sind Kommandozeilen-Tools wie jq oder Pythons csv-Modul effizienter.

Warum gehen bei meiner XML-Konvertierung Daten verloren?

Die häufigste Ursache sind verworfene XML-Attribute. Stellen Sie sicher, dass Attribute im Konverter erhalten bleiben. Prüfen Sie außerdem auf XML-Namespaces — Elemente wie ns:item werden zu literalen Schlüsselnamen in JSON.

Kann ich eine CSV-Datei direkt in XML konvertieren?

Nicht direkt mit einem einzigen Tool. Konvertieren Sie CSV zuerst mit unserem CSV-zu-JSON-Konverter in JSON und dann das JSON mit unserem JSON-zu-XML-Konverter in XML. Zwei Schritte, derselbe Browser, keine hochgeladenen Daten.

Warum geht bei HTML zu Markdown meine Formatierung verloren?

Markdown ist bewusst eingeschränkt — es deckt 80 % der gängigen Formatierungsbedürfnisse ab. CSS-Styling, benutzerdefinierte Klassen und komplexe Layouts haben kein Markdown-Äquivalent.

Was ist das beste Format für API-Antworten?

JSON ist der Standard für REST-APIs. Es bietet die beste Parser-Unterstützung, die kleinste Nutzlastgröße für typische strukturierte Daten und native Unterstützung in JavaScript. Verwenden Sie XML nur für SOAP-APIs oder die Integration älterer Unternehmenssysteme.