twineconvert

free · in-browser · no upload

VCF to JSON
Converter

Drop your VCF file. We'll convert it to JSON right here in your browser, your file never leaves your device.

or drop your file

Select your file here to get started

or drop your file here.

Accepts .vcf, .vcard

nothing uploaded no file size cap no signup

How it works

Three steps. No upload, no signup.

  1. 1

    Drop your file

    Click the dropzone above or drag a VCF from your desktop. Files of any size, there's no upload, so there's no upload limit.

  2. 2

    Convert in your browser

    The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.

  3. 3

    Download

    Get your JSON the moment the conversion finishes. Convert another, or close the tab.

Files stay on your device

Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.

No file size limit

Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.

Free, no signup, no ads on conversions

No account required. No watermark on the output. No queue. Drop a file, get a converted file.

Why convert VCF → JSON

What this conversion is actually for

If you are scripting against contacts (a sync job, a dedupe tool, an import pipeline) JSON is far easier to work with than raw vCard line folding and escaping. This gives you a clean array of contact objects with predictable keys.

A real example

You are writing a script to merge contacts from three sources. Convert each .vcf export to JSON here, load the arrays, dedupe by email in code instead of parsing vCard by hand.

Troubleshooting

I expected nested fields and got flat ones.

The output is intentionally flat (one object per contact with string fields) so it maps cleanly to a spreadsheet or a simple import. If you need structured N/ADR components, that is a different shape; ask and we can add a variant.

"No contacts found".

The file is probably not vCard. Open it and confirm it has BEGIN:VCARD / END:VCARD blocks. An exported CSV renamed .vcf will not parse.

Formats involved

About VCF and JSON

VCF, VCF

VCF is a file format we support converting. Detailed format information is being added, for now, drop your file in the converter above and you'll get the conversion you came for.

How to open

Most operating systems open this format with a default application; if not, search for a free reader/viewer for the format.

JSON, JavaScript Object Notation

JSON is a lightweight text format for structured data, nested objects, arrays, strings, numbers, booleans. It's the lingua franca of web APIs, configuration files, and data interchange between programs. Human-readable when formatted, machine-parseable in every programming language, and roughly half the size of equivalent XML.

How to open

Any text editor reads JSON. Browsers display .json files in a formatted tree view. VS Code and similar editors highlight syntax.

Related tools

Convert other files to JSON

Convert your VCF to other formats

FAQ

Common questions

Is this VCF → JSON converter really free?

Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.

Where does my file go when I convert it?

Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.

What's the maximum file size?

Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.

Why convert VCF to JSON?

File interchange. API responses, configuration files, structured data interchange. The most common reason to convert is compatibility, JSON works in places where VCF doesn't, or vice versa.

How do I open a VCF file in the first place?

Most operating systems open this format with a default application; if not, search for a free reader/viewer for the format.

Does this work offline?

Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.

Can I convert multiple files at once?

Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.