DataFmt

Free · Secure · Runs in your browser

Free Online Data Format Converter

Convert between CSV, JSON and Markdown tables right in your browser. No sign-up, no upload, instant and privacy-friendly.

Drag & drop a file here, or click to upload
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Why DataFmt

Client-side only

Every byte is parsed and converted inside your browser. Your data never leaves the device, which keeps sensitive content safe.

Zero setup

No account, no installation. Paste your text, drop a file, or upload one and you are ready to go.

SEO-friendly & bilingual

Every converter has its own URL with pre-rendered content, plus English and Chinese versions for global users and search engines.

Free for any use

Personal, open-source or commercial — DataFmt is free to use with no hidden limits.

Pick a converter

Each tool page includes a full guide and FAQ. Click a card to open its dedicated workspace.

CSV to JSON

CSV to JSON

Turn any CSV table into clean JSON with a single click.

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JSON to CSV

JSON to CSV

Export JSON arrays to CSV that opens cleanly in Excel or any database.

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CSV to Markdown

CSV to Markdown

Turn a CSV table into a GitHub-flavoured Markdown table ready to paste.

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Markdown to CSV

Markdown to CSV

Pull a Markdown table out of any document and turn it into clean CSV.

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JSON Formatter

JSON Formatter

Turn compressed JSON into a readable, well-indented layout. Optionally sort keys for stable diffs.

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JSON Minifier

JSON Minifier

Strip whitespace and newlines from JSON to reduce payload size for URLs, QR codes or environment variables.

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JSON Validator

JSON Validator

Quickly check whether JSON is valid and pinpoint errors down to the line and column.

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JSON to YAML

JSON to YAML

Convert JSON into more readable, hand-editable YAML.

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YAML to JSON

YAML to JSON

Turn YAML configuration into JSON that scripts and services can consume directly.

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JSON to XML

JSON to XML

Emit XML from JSON for integration with enterprise systems and legacy services.

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XML to JSON

XML to JSON

Parse XML into structured JSON that frontends and scripts can use directly.

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JSON Diff

JSON Diff

List added, removed and changed fields across two JSON documents, organised by path.

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JSON Escape

JSON Escape / Unescape

Convert between raw text and JSON string literals without hand-escaping backslashes, quotes and newlines.

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XML Formatter

XML Formatter / Minifier

Format XML for readability or minify it for transport — switch modes with one click.

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SQL Formatter

SQL Formatter

Beautify SQL across dialects to make long queries easier to review and share.

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Your data stays with you

DataFmt performs all parsing and conversion in the browser. We do not log, store or transmit the content you paste or upload. It is safe to use on sensitive spreadsheets, personal exports and internal reports.

Privacy

Typical scenarios

Data analysis & migration

Turn CSV exports from a database into JSON for scripts, or export API responses as CSV for BI tools.

Technical writing

Generate Markdown tables for README files, blog posts and internal wikis in one click.

Team collaboration

Exchange structured data with frontend, backend, product and QA team-mates without manual editing mistakes.

Education & reporting

Transform spreadsheet data into formats that embed cleanly in lectures, training decks and reports.

Tools by category

Grouped by intent, not by tech. Pick the right tool for the job in seconds.

Why choose a browser-local data format converter?

Structured data formats come and go. CSV was born for spreadsheets, JSON rose with Web APIs, YAML and TOML took over configuration, and XML is still deeply embedded in enterprise systems. In real workflows a single field travels across these formats multiple times — out of a database, through a script, into a document or a UI. Each hop is a chance for data loss or corruption, which is why moving between formats quickly and safely is a recurring challenge for every developer and data practitioner.

Most online converters follow an upload-process-download pattern: the data leaves your machine, is processed on a server, and comes back. That model has three structural problems. First, the data is at risk during transfer and storage — unacceptable for customer records, internal reports or personal information. Second, throughput is bound by network bandwidth and server limits. Third, you generally cannot verify what the provider does with the data afterwards. For serious work, these risks simply do not add up.

DataFmt takes a different path. Every conversion runs inside your browser, using JavaScript or WebAssembly under the hood. The data never leaves your device. Even offline — once the page has loaded — the tools keep working. You get the privacy guarantees of a local CLI with the convenience of a shareable URL.

The trade-off is real but manageable. A browser is not the right place to transform gigabyte-scale datasets; in those cases pair DataFmt with jq, csvkit, Pandas or a proper data pipeline. We also cannot ship every dialect of every format. DataFmt is optimised for everyday, small-to-medium workloads where correctness and privacy come first.

For developers, data analysts and technical writers, DataFmt lives as a quick pit-stop in the toolchain. Need to drop an API response into a README? Use CSV → Markdown. Need to eyeball differences between two JSON snapshots? Use JSON Diff. Translating YAML config into XML for a legacy service? Route through JSON. Every tool has its own URL, full tutorial and FAQ, so it is easy to bookmark, share and adopt across a team.