ConvertKit — Convert anything, instantly

⇄

Getting started

Browser native

ConvertKit converts files between 12 format pairs — entirely inside your browser. No account, no upload, no server. Open the page, pick your conversion, and go.

1

Pick a route — the 12 route buttons at the top of the tool update the input area automatically.

2

Add content — text-based routes accept typed or pasted input. File routes need a file upload via drag-and-drop or Browse.

3

Set options (optional) — Title, Font, Sheet name, or JSON indent appear automatically when relevant.

4

Click ⇄ Convert — preview the output, then download with one click.

✓

No file size limit. The only constraint is your device's memory, which is rarely an issue for normal documents and spreadsheets.

⚙

How it works

Every conversion runs in one of two modes depending on the output format.

Mode	Routes	How
Instant	JSON↔CSV, CSV→JSON, HTML→TXT, HTML→MD, MD→HTML, JSON→TXT	Pure JavaScript string manipulation in memory. Works completely offline. Zero delay.
Library CDN auto-loaded	TXT→PDF, DOCX→PDF, TXT→DOCX, CSV→XLSX, XLSX→CSV, PDF→TXT	A small library loads from CDN the first time that route is used. Subsequent uses are instant (browser cached).

ℹ

CDN libraries are loaded lazily — only when first used. If you only ever use JSON→CSV, nothing is ever downloaded.

🔒

Privacy & security

Your files and content never leave your device. All conversion logic runs entirely inside your browser tab.

What	Status
File upload to server	Never. Files are read via browser File API only.
Content sent over network	Never. Zero data transmitted except CDN library scripts.
Local storage / cookies	Not used. Nothing persists after you close the tab.
Analytics or tracking	None. No third-party trackers of any kind.
CDN libraries	Loaded from trusted CDNs (cdnjs, unpkg) as scripts only — they never see your file content.

PDF

Text → PDF

Auto CDN · jsPDF

Converts typed or pasted text into a formatted .pdf document. Supports multi-page output, optional title with a rule, and three font choices. Long text wraps and paginates automatically.

Option	Type	Description
Title	string	Heading printed at top with a horizontal rule. Also used as the filename.
Font	select	Helvetica (default), Times, or Courier.

💡

Use blank lines to separate paragraphs. Single newlines become line breaks within the same block.

TXT

PDF → Text

Auto CDN · pdf.js

Extracts all readable text from a .pdf file using Mozilla's pdf.js. Each page is prefixed with a --- Page N --- separator. Ideal for copying content out of documents.

⚠

Scanned PDFs (images of text) will return empty output — they have no text layer. Use OCR software first to create a text-embedded PDF.

PDF

DOCX → PDF

Auto CDN · mammoth + jsPDF

Converts a Word .docx file to PDF. Uses mammoth.js to extract text and structure, then jsPDF to render it. Paragraphs and line breaks are preserved.

⚠

Tables, images, and columns are not preserved. For pixel-perfect layout, use Word's built-in "Save as PDF" instead.

Option	Type	Description
Title	string	Override the PDF heading. Defaults to the filename.
Font	select	Helvetica, Times, or Courier.

DOCX

Text → DOCX

Auto CDN · docx.js

Converts text into a real .docx Word document that opens in Microsoft Word, Google Docs, and LibreOffice. Blank-line-separated blocks become separate Word paragraphs.

paragraph formatting

// Blank lines → separate paragraphs in Word First paragraph here. Second paragraph starts after blank line. // Single newlines → line breaks within paragraph Line one. Line two (same paragraph).

XLSX

CSV → Excel

Auto CDN · SheetJS

Converts a .csv file to a proper .xlsx Excel spreadsheet. Column detection is automatic and the sheet tab name can be customised. Numbers are preserved as numeric cells.

Option	Type	Description
Sheet name	string	The worksheet tab name in Excel. Defaults to "Sheet1".

💡

SheetJS auto-detects comma, semicolon, and tab delimiters. Most CSV files just work without any configuration.

CSV

Excel → CSV

Auto CDN · SheetJS

Exports the first sheet of an .xlsx Excel file as a UTF-8 .csv. Formulas are resolved to their computed values. Cell formatting is removed. Compatible with databases, Python pandas, Google Sheets, and any CSV reader.

ℹ

First sheet only. If the Excel file has multiple sheets, only the first one is exported.

CSV

JSON → CSV

No CDN · Instant

Converts a JSON array of objects into a CSV spreadsheet. All unique keys across all objects become column headers. Missing values in any row are left as empty cells.

required input format

// ✅ Array of objects [ { "name": "Ali", "age": 25, "city": "Lahore" }, { "name": "Sara", "age": 30, "city": "Karachi" } ] // ❌ Single object — wrap in [ ] first { "name": "Ali", "age": 25 }

JSON

CSV → JSON

No CDN · Instant

Parses any CSV content into a JSON array of objects. The first row becomes the object keys. Numeric values are automatically cast to numbers. Handles quoted fields and commas inside values correctly.

example

// Input CSV name,score,city Ali,95,Lahore Sara,87,Karachi // Output JSON [ { "name": "Ali", "score": 95, "city": "Lahore" }, { "name": "Sara", "score": 87, "city": "Karachi" } ]

HTML

Markdown → HTML

No CDN · Instant

Converts Markdown into a complete, self-contained .html file with an embedded stylesheet. Supports headings h1–h6, bold, italic, inline code, fenced code blocks, blockquotes, links, images, horizontal rules, and unordered lists.

supported syntax

# Heading 1 ## Heading 2 **bold** *italic* ~~strikethrough~~ `code` ```js const x = 1; ``` - list item > blockquote --- [link](url) ![alt](image.png)

MD

HTML → Markdown

No CDN · Instant

Strips HTML tags and converts the structure into clean Markdown. Handles headings, bold, italic, code, pre blocks, links, images, list items, blockquotes, and horizontal rules. Automatically extracts <body> from full HTML pages.

💡

Paste a full HTML page — the converter automatically ignores the <head> and extracts only the body content.

TXT

HTML → Text

No CDN · Instant

Strips all HTML tags and extracts clean, readable plain text. Block elements (headings, paragraphs, list items) are separated by newlines. HTML entities like & and   are decoded automatically.

TXT

JSON → Text

No CDN · Instant

Pretty-prints any JSON value as indented plain text. Useful for reading complex API responses or config files in a human-readable format without a JSON viewer.

Option	Type	Description
JSON indent	select	2 spaces (default) or 4 spaces per level of nesting.

📦

Libraries used

These libraries are loaded automatically from CDN the first time a route that needs them is used. If you never use that route, they are never downloaded.

Library	Version	Used for	Source
jsPDF	2.5.1	TXT→PDF, DOCX→PDF output rendering	cdnjs
pdf.js	3.11.174	PDF→TXT text extraction	cdnjs
mammoth.js	1.6.0	DOCX→PDF text and structure extraction	cdnjs
docx.js	8.5.0	TXT→DOCX Word file generation	unpkg
SheetJS (xlsx)	0.18.5	CSV→XLSX and XLSX→CSV conversion	cdnjs

✓

All six text-based routes — JSON↔CSV, HTML→TXT, HTML→MD, MD→HTML, JSON→TXT — use zero external libraries. Pure browser JavaScript.

🔧

Troubleshooting

Problem	Cause	Fix
PDF→TXT returns nothing	PDF is a scanned image with no text layer	Use OCR software (Adobe Acrobat, online OCR tools) to create a text-embedded PDF first
DOCX→PDF loses formatting	Tables, images, and columns aren't preserved	This is a text-extraction conversion. For layout-perfect PDF use Word's built-in "Save as PDF"
JSON→CSV: "must be an array"	Input is an object `{"{"}...{"}"}` not an array	Wrap the object: `[{"{"} ... {"}"}]`
Excel opens with wrong characters	Encoding mismatch on special characters	Open Excel → Data → From Text/CSV → choose UTF-8 encoding
CDN library fails to load	No internet on first use of that route	Connect to internet and retry. Browser caches the library after first load
Nothing happens on Convert	Input is empty or wrong file type	Check the status bar below the converter for the exact error message
MD→HTML missing syntax	Complex or non-standard Markdown extensions	The parser supports CommonMark basics. GFM tables and task lists are not yet supported

Convert anythingto anything. Instantly.

Everything you can convert

Three steps. That's it.

Questions

Documentation