CSV to JSON Converter Online — Free & Private

Choose delimiter and whether row one holds headers; uneven rows pad deterministically with warnings — no silent truncation beyond documented drops.

Options

CSV input (parsing)

First row contains column names

JSON output (serialization)

Indent

Sort object keys recursively

Conversion result

Ready

Paste input and click Convert to see the result summary here.

CSV source

0chars0 B1lines

JSON output

0chars0 B1lines

All conversions run in your browser. Nothing is uploaded to FastMinify.

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CSV → JSON — spreadsheets to API-ready arrays

Covers delimiter guessing UX plus deterministic padding behaviour.

Developer notes

• Parser rejects unclosed quotes loudly. • Extra columns trimmed with warnings — review toast output. • All cell values remain strings — cast numbers/bools in your service.

When teams pick this route

• Glueing CRM CSV dumps into fetch() bodies. • Importing vendor grids before JSON Schema validation.

About these options

CSV exports: choose a delimiter (Auto follows locale — semicolon on /fr), RFC-minimal vs always-quoted fields, line endings, and whether to emit a header row. CSV imports: delimiter is auto-detected from the first line (comma, semicolon, tab, or pipe) — toggle whether row 1 holds column names. JSON output (XML, YAML, or CSV sources): indentation (including compact one-line) and optional recursive key sort. JSON → XML: toggle pretty-printing and indent width. YAML output: indent width, readable vs tighter layout, and deterministic string quoting (there is no source YAML file to “preserve”). XML comments are not represented in the intermediate JSON tree.

Worked examples

Header row

Sample input

sku,name,qty,price
WB-001,Wireless Ergonomic Mouse,120,24.99
WB-002,USB-C Hub Pro Adapter,85,49.50
WB-003,Mechanical Keyboard RGB,42,89.00
WB-004,Adjustable Monitor Stand,67,35.25

Sample output

[
  {
    "sku": "WB-001",
    "name": "Wireless Ergonomic Mouse",
    "qty": "120",
    "price": "24.99"
  },
  {
    "sku": "WB-002",
    "name": "USB-C Hub Pro Adapter",
    "qty": "85",
    "price": "49.50"
  },
  {
    "sku": "WB-003",
    "name": "Mechanical Keyboard RGB",
    "qty": "42",
    "price": "89.00"
  },
  {
    "sku": "WB-004",
    "name": "Adjustable Monitor Stand",
    "qty": "67",
    "price": "35.25"
  }
]

Semicolon regional file

Sample input

id;city;country
1;Paris;FR
2;Berlin;DE
3;Madrid;ES
4;Rome;IT

Sample output

[
  {
    "id": "1",
    "city": "Paris",
    "country": "FR"
  },
  {
    "id": "2",
    "city": "Berlin",
    "country": "DE"
  },
  {
    "id": "3",
    "city": "Madrid",
    "country": "ES"
  },
  {
    "id": "4",
    "city": "Rome",
    "country": "IT"
  }
]

Navigate related converters

Go hierarchical with CSV → YAML, markup via CSV → XML, or revisit JSON → CSV for exports.

CSV → JSON FAQ

Parser guarantees

Why strings only?

CSV carries opaque text — FastMinify avoids guessing numeric types.

Embedded newlines inside quotes?

Supported when wrapped in double quotes per RFC-style parsing.

UTF-8 BOM?

Stripped automatically.

Multiple header rows?

Only row one participates — preprocess upstream.

CSV

Convert CSV to JSON, XML, YAML, TOML and TSV.

CSV → XML

CSV → YAML

CSV → TOML

CSV → TSV

Other converter families

JSON

Convert JSON to YAML, XML, CSV, TOML, TSV, SQL, HTML, Properties and INI — all in your browser.

YAML

Convert YAML to JSON, XML, CSV, TOML, TSV, Properties and INI — cross-target TOML via Properties → TOML and INI → TOML in alsoLinks.

XML

Convert XML to YAML, CSV, JSON, TOML, TSV and HTML.

TOML

Convert TOML to JSON, YAML, XML, CSV, Properties and INI.

TSV

Convert tab-separated values to JSON and CSV.

SQL

Parse INSERT statements to JSON and CSV.

HTML

Convert HTML to JSON, XML, YAML and Markdown.

Markdown

Convert Markdown to HTML locally.

Properties

Convert Java .properties files to JSON, YAML, INI and TOML.

INI

Convert INI configs to JSON, YAML, Properties (flat INI only) and TOML.

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Unminify

Expand minified or compressed code — unminify JavaScript, CSS, TypeScript, SCSS, LESS, SQL, YAML and other formats when debugging or reviewing.

CSS preprocessors

Compile SCSS or LESS to standard CSS in the browser — pair with beautify or minify for a full stylesheet workflow.

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DevOps & Infra

Terraform HCL format/validate/minify, Dockerfile format & lint, Docker Compose and .env validation.

CI/CD

GitHub Actions and GitLab CI — format YAML and check workflow/job structure in your browser.

Logs & observability

Line-oriented JSON/NDJSON and Nginx/Apache access logs — format, filter, validate, and CSV/TSV.

Kubernetes

Multi-doc manifests, structural validate, Ingress/Deployment starters, and Helm values formatting.

Networking / IP

CIDR, subnets, and IPv4/IPv6 helpers — in your browser.

Security & tokens

JWKS, X.509 certificates, and secrets scan — browser-local.

API & schemas

OpenAPI tools to format, validate, and lint your specs.

Encoding

Encode or decode Base64, URL components and HTML entities — client-side only.

Developer utilities

Timestamps, UUID, ULID, Nanoid, cron, passwords, regex, slugify, number bases, case, text diff, and chmod — all client-side.

Text & Markdown

Count words, build Markdown TOCs, and clean line lists — all in your browser.

AI & LLM

Token counting, pricing estimates, and context-window fit — 100% browser-local.

Serialization

Serialize and deserialize PHP data structures beside JSON workflows.