twineconvert

free · in-browser · no upload

GEDCOM to JSON
Converter

Drop your GEDCOM 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 .ged, .gedcom

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 GEDCOM 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 GEDCOM → JSON

What this conversion is actually for

GEDCOM is the universal genealogy interchange format, but its line-prefixed level-numbered structure (`0 @I1@ INDI`, `1 NAME John /Smith/`, etc.) is brutal to parse manually or work with in modern tools. JSON gives you a hierarchical object you can hand to any web app, Node script, or visualization library without writing a custom parser.

A real example

You exported your family tree from Ancestry, MyHeritage, or Family Tree Maker as a .ged file. You want to build a small React/Svelte/D3 app that visualizes it. Drop the .ged here, get JSON with individuals, families, sources, and event references already linked by ID. Skip writing the parser entirely.

Troubleshooting

Custom tags from my software (e.g., _UID, _PHOTO) appear with leading underscores.

GEDCOM uses underscore prefixes for non-standard tags. We preserve them in the JSON output as-is so software round-tripping back to GEDCOM keeps custom data intact. If you don't need them, filter them out at the JSON level.

Dates in the JSON are strings, not parsed dates.

GEDCOM date strings are deeply weird ('ABT 1850', 'BEF JUN 1923', 'BET 1900 AND 1910', non-Gregorian calendars). Forcing them into ISO dates would lose information. We output them as the original strings; parse at your application layer where you know what loss is acceptable.

Family relationships seem incomplete.

GEDCOM splits people (INDI) and families (FAM) into separate records linked by IDs (HUSB, WIFE, CHIL). The JSON preserves both. To traverse, look up family.husb / wife / chil IDs against the individuals object.

Formats involved

About GEDCOM and JSON

GEDCOM, Genealogical Data Communication

GEDCOM is the universal interchange format for family-tree data. The current spec is GEDCOM 7.0 (2021) but most genealogy software still emits GEDCOM 5.5.1 (2019) for compatibility. Plain-text hierarchical records: 0-level lines define individuals (INDI) and families (FAM); deeper levels (1, 2, 3...) attach attributes like names, dates, and places. Every major genealogy app reads and writes GEDCOM.

How to open

Ancestry, MyHeritage, FamilySearch, RootsMagic, Family Tree Maker, Gramps, MacFamilyTree. Plain text in any editor.

Full GEDCOM format guide →
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.

Full JSON format guide →

You may also need

More tools people use alongside this one

Related tools

Convert other files to JSON

Convert your GEDCOM to other formats

FAQ

Common questions

Is this GEDCOM → 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 GEDCOM to JSON?

Family tree interchange between genealogy programs. API responses, configuration files, structured data interchange. The most common reason to convert is compatibility, JSON works in places where GEDCOM doesn't, or vice versa.

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

Ancestry, MyHeritage, FamilySearch, RootsMagic, Family Tree Maker, Gramps, MacFamilyTree. Plain text in any editor.

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.