CSV Tools

Data tools format, convert, and validate the structured payloads developers move between APIs, spreadsheets, and databases, JSON for HTTP bodies, CSV for analytics exports, XML for legacy SOAP endpoints, YAML for config files, SQL for inserts. A backend engineer wiring a Stripe webhook into a Postgres warehouse can paste the raw JSON, validate it, flatten a nested array, then ship CSV to the BI team, all in three browser tabs. This category collects 103 free tools covering every common transform: JSON ↔ CSV, YAML ↔ JSON, XML ↔ JSON, format, minify, diff, validate. Client-side, no sign-up.
What you can do with Data Tools

Format and validate structured payloads, paste a minified API response into json-formatter-validator for indented output with red-underlined errors, or run validate-json for a pass/fail check.
Convert between data formats, csv-to-json, json-to-csv, yaml-to-json, and xml-to-json cover the four conversions every backend dev runs weekly.
Compare two payloads field-by-field, json-diff highlights what changed between two API responses.

Reach for Data tools when the input is a structured payload, JSON, CSV, XML, YAML, SQL, TOML, and the goal is reshaping it without changing the meaning. If the work is wrapping the same bytes in a different transport (Base64, URL-encoded, hex), Encoding Tools is closer. For regex, character counting, or case conversion on free-form prose, Text Tools handles it. For cron expressions, JWT decoding, or curl-to-fetch translations, Developer Tools is the right stop.
The Data Tools toolkit

Tool
What it does
When to use

JSON Formatter & Validator
Pretty-prints JSON and flags syntax errors inline.
Reading a 4 KB minified API response that arrived as one long line.

CSV to JSON
Converts a CSV with headers into a JSON array of objects.
Loading a 5,000-row marketing export into a Node.js seed script.

JSON to CSV
Flattens a JSON array of objects to a CSV with a header row.
Handing API results to an analyst who only opens spreadsheets.

YAML to JSON
Converts a YAML config into the equivalent JSON document.
Porting a Helm chart values file into a JSON-only schema validator.

XML to JSON
Parses an XML document into a JSON tree.
Reading a legacy SOAP response inside a fetch-based JavaScript app.

JSON Minifier
Strips whitespace for tighter payloads.
Shaving 30% off a config file before embedding it in an HTML attribute.

JSON Diff
Highlights added, removed, and changed fields between two JSON docs.
Spotting which field a release broke between yesterday’s API and today’s.

SQL Formatter
Indents and aligns SQL, keywords uppercase, joins on their own line.
Cleaning up a 200-line query someone pasted as one wrapped blob.

JSON to TypeScript
Generates a TypeScript interface from a JSON sample.
Typing a third-party API response without writing the interface by hand.

Excel to HTML Table
Converts an XLSX sheet into a clean HTML <table>.
Embedding a pricing table from finance into a marketing page.

CSV Viewer
Renders a CSV as a sortable, paginated grid in the browser.
Skimming a 50 MB log export without waiting on Excel to load.

JSON to SQL
Generates INSERT statements from a JSON array of records.
Seeding a test database from a JSON fixture checked into the repo.

Formatters and validators clean up unreadable payloads. json-formatter-validator is the daily driver; sql-formatter does the same for queries; validate-json gives a pass/fail when the only question is “does it parse?”.
Format converters translate the same data between dialects. csv-to-json and json-to-csv cover the spreadsheet/API boundary; yaml-to-json and xml-to-json bridge configs and legacy services into JSON tooling.
Code generators turn data into typed scaffolding. json-to-typescript writes interfaces from a sample; json-to-sql writes seed inserts; json-schema-generator writes a JSON Schema for runtime validation.
How to choose the right data tool

If the payload arrived minified on one line → start with json-formatter-validator.
If a CSV came from finance and a Node service needs to read it → run csv-to-json and pipe the output in.
If yesterday’s and today’s API responses disagree → drop both into json-diff.
If an XML file from a SOAP service needs parsing in a fetch-based app → xml-to-json avoids pulling in a DOMParser dependency.
If the goal is to generate types from a sample API response → json-to-typescript writes the interface in one paste.

The trade-off worth knowing: browser tools handle anything under ~10 MB without slowdown, but a 200 MB CSV export will lock the tab. Past that line, command-line tools (jq, csvkit, yq) are faster. Browser tools win on speed of access and on privacy, the data never leaves the laptop.
Frequently asked questions
Q: What’s the difference between a JSON formatter and a JSON validator?
A formatter rewrites JSON with indentation so a human can read it; a validator checks whether the JSON parses against the spec, or against a schema, if one is supplied. Most browser tools combine both. json-formatter-validator pretty-prints and flags syntax errors in one pass; validate-json is the lighter pass/fail version.
Q: How do I convert a CSV with a custom delimiter to JSON?
First, normalize the delimiter. change-csv-delimiter swaps semicolons or pipes for commas. Then run csv-to-json on the cleaned file. If the source uses tabs, convert-tsv-to-json skips the middle step. For rows where columns are missing, fill-incomplete-csv-records pads them first so the JSON output stays uniform.
Q: Is YAML or JSON better for config files?
YAML wins on readability when humans edit the file, comments are allowed, quotes are optional, and indentation maps to nesting. JSON wins on parser speed and tooling, every language ships a JSON parser, while many need a third-party YAML library. Kubernetes, GitHub Actions, and Ansible chose YAML; most public APIs chose JSON. Use yaml-to-json to feed a JSON-only consumer.
Q: How do I diff two JSON files without losing track of array order?
json-diff compares two JSON documents key-by-key and highlights added, removed, and changed fields. By default it treats array order as significant, [1, 2] and [2, 1] count as different. For order-independent comparison, sort both arrays with json-sorter first, then diff the canonical versions.
Q: Can I generate a TypeScript interface from a JSON API response?
Yes, paste a sample response into json-to-typescript and it writes a matching interface. Optional fields come from inferring across multiple samples; for richer typing, generate a JSON Schema with json-schema-generator first, then run a Schema-to-TypeScript converter. The same approach feeds json-to-java-pojo for Spring services.
Q: Why is my JSON file failing to parse?
Five common reasons: a trailing comma after the last array or object element (illegal in JSON, legal in JS), single quotes instead of double quotes, unescaped backslashes inside strings, comments (JSON doesn’t allow them), and unquoted keys. json-formatter-validator names the line and column on each error. If the file is JSON5 or JSONC, strip the comments first.
Related categories
Developer Tools cover JWT decoding, cron parsing, regex testing, and curl-to-fetch, the non-payload utilities a backend engineer pairs with these. Encoding Tools handle Base64, URL encoding, and hex when the data needs a different transport. For free-form prose, Text Tools is the next stop.