Universal workbench

Email JSON to EML email

Create EML email from Email JSON locally, with no upload or account.

Device-onlyNo uploads. Ever.

Pipelines, branches, presets, naming, and detailed controls

Display

Text sizeDensity High contrast Monospace editor

Quick start

JSON → YAML WebP → PNG SVG → React JSX Plain text → Base64

From

Help me choose the best output Suggested: EML email

What matters most?

Recommendations use the registered target format and tested fidelity classification. They never inspect or upload your content.

01Input

Drop files or a folder hereChoose Email JSON files or a folder — batch input is welcome

Choose files Choose folder

or paste content

02Configure & run

Email JSONEML email

structural conversion · single or batch

Conversion preflightSize, memory, engine, execution, and fidelity before you start

Input: 226 B
Estimated peak memory: 16 MiB
On-demand download: No large engine download
Execution: Responsive local worker
Fidelity: No lossy step declared

What to providePaste valid Email JSON syntax or drop one or more .email.json files.What you’ll getProduces previewable EML email text and a correctly named download.

Output naming & batch behavior

Filename templateAvailable variables: {output} (converter’s meaningful name), {name}, {target}, {ext}, {index}. Duplicate names receive a safe numeric suffix.

Exampleoutput.eml

Pipeline 1 linear · 0 branches

Why use A → B → C?

A pipeline feeds each result directly into the next compatible converter. Use one when the destination needs an intermediate representation or when you want to inspect and normalize that middle format.

JSON → CSV → XLSX turns records into rows before building a workbook.
Markdown → HTML → DOCX resolves markup before creating a document.
SVG → PNG → PDF intentionally flattens vector artwork before placing it on a page.

Only type-compatible next steps are offered. Lossy steps are marked before you run them.

1Email JSON to EML emailstructural

Add compatible step

Parallel output branchesEach branch receives the final linear result. Branches do not feed or depend on one another.

Add a parallel destination

Processing happens locally. Your file bytes are never sent anywhere.

About this conversion

How to convert Email JSON to EML email

Before you start

Paste valid Email JSON syntax or drop one or more .email.json files.

Accepted: .email.json · application/json

Paste valid Email JSON content, choose files, or drag them onto the drop zone.
Confirm the detected format. Mixed-format batches are flagged before conversion.
Select “Convert on this device.” Produces previewable EML email text and a correctly named download.

How this converter behaves

The source records are parsed into a small, typed interchange model and serialized into the destination format with explicit fidelity limits.

What happens to your data?

The conversion engine runs in this browser tab. OmniCastConverter has no upload API and never sends your content, file name, or converted result to a server.

Fidelity and limitations

This route is classified as structural. The converter preserves meaning and structure supported by both formats.

The normalized representation preserves common address, subject, date, message ID, and readable body fields. MIME attachments, rich HTML alternatives, signatures, DKIM results, and provider-specific headers are not preserved.
EML output accepts exactly one normalized message. Use MBOX when the Email JSON array contains multiple messages.

Try a valid example

The “Use example” action in the workbench loads this exact input. Produces previewable EML email text and a correctly named download.

[{"from":"Ada <ada@example.com>","to":"local@example.test","cc":"","subject":"Private conversion","date":"Thu, 23 Jul 2026 09:00:00 +0000","messageId":"<local-example@example.com>","body":"This message stays in the browser."}]