---
title: "Developer Tools for JSON, Encoding and Data"
description: "Format and validate JSON, convert CSV and YAML, test regular expressions, decode text and inspect data. Developer utilities that run in your browser."
url: https://candoya.com/tools/dev/
locale: en
type: tool-category
---

# Developer and data tools

A small payload should not require a new project just to inspect it. Use JSON Formatter to expand compact data, JSON Validator to locate a syntax problem, or JSON Minifier to remove insignificant whitespace. CSV, YAML, XML and TOML tools handle common handoffs between applications. Regular expression, URL and encoding utilities help isolate the part of an input that needs attention. Processing happens in your browser, including text you paste into an editor.

Choose validation according to the question. Valid JSON syntax does not prove that a payload has the fields your API requires; that needs a schema or application-specific checks. Similarly, decoding a JWT reveals its claims but does not verify its signature. Base64 is an encoding, so anyone with the encoded value can recover the original. Hashing and encryption tools serve different purposes and should be selected accordingly.

Conversions also involve choices. A CSV value such as 00123 might be an identifier whose leading zeros matter. Nested JSON does not always map neatly to spreadsheet columns, and XML attributes need a representation in JSON. Read each tool's mapping rules, inspect a short sample first and compare the exported result with the original before using it in a larger workflow.

## Developer tools

- [Base64 Encode and Decode](https://candoya.com/tools/base64-encode-decode/): Free online Base64 encoder and decoder. Convert text to Base64 and back instantly, with full Unicode and URL-safe support. No upload, runs in your browser.
- [CIDR Range Calculator](https://candoya.com/tools/cidr-range-calculator/): Convert an IPv4 or IPv6 range to the smallest exact CIDR list, or expand a CIDR block to its first and last address. Free and private.
- [Cron Expression Builder](https://candoya.com/tools/cron-expression-builder/): Build and validate standard 5-field cron expressions online. Get a plain-language schedule preview and next run times in UTC.
- [Cron Expression Explainer](https://candoya.com/tools/cron-expression-explainer/): Paste a five-field cron expression and read its plain-English meaning, field breakdown and next UTC run times instantly in your browser.
- [CSS Clamp Calculator](https://candoya.com/tools/css-clamp-calculator/): Free CSS clamp calculator for fluid typography and responsive spacing. Generate clamp(), slope, intercept and copyable CSS in your browser.
- [CSS Formatter](https://candoya.com/tools/css-formatter/): Free CSS formatter to beautify minified or messy stylesheets online. Choose indentation, check structure, copy or download CSS in your browser.
- [CSS Minifier](https://candoya.com/tools/css-minifier/): Free CSS minifier to compress stylesheets online. Remove comments and extra whitespace, measure bytes saved, then copy or download locally.
- [CSV to JSON Converter](https://candoya.com/tools/csv-to-json/): Convert CSV to JSON online with header, delimiter and type controls. Handles quoted commas and multiline fields privately in your browser.
- [CSV to YAML Converter](https://candoya.com/tools/csv-to-yaml/): Free online CSV to YAML converter. Paste CSV and get clean YAML instantly, with header keys, type detection and auto delimiter. Runs in your browser.
- [NanoID Generator](https://candoya.com/tools/nanoid-generator/): Generate secure, URL-friendly NanoID unique IDs online. Pick the length, alphabet and quantity, copy in one click. Runs in your browser, nothing uploaded.
- [IEEE 754 Float Converter](https://candoya.com/tools/ieee-754-float-converter/): IEEE 754 converter for 32-bit floats and 64-bit doubles. Convert decimal to hex or binary, decode raw bits, and inspect every field locally.
- [Number Base Converter](https://candoya.com/tools/number-base-converter/): Free number base converter. Convert between binary, octal, decimal and hexadecimal instantly, plus any base from 2 to 36. Runs in your browser.
- [ULID Generator](https://candoya.com/tools/ulid-generator/): Generate ULIDs online in bulk. Create sortable 26-character Crockford Base32 IDs, copy one or all, and keep monotonic order. Runs in your browser.
- [Unicode Character Lookup](https://candoya.com/tools/unicode-character-lookup/): Look up any Unicode character or code point. See its name, U+ value, decimal number, UTF-8, UTF-16, HTML, JavaScript, and CSS encodings.
- [Clipboard Inspector](https://candoya.com/tools/clipboard-inspector/): Free clipboard inspector to see every format on your clipboard - plain text, HTML, images and custom types - with byte sizes and previews. Runs in your browser.
- [HTML Entity Encode and Decode](https://candoya.com/tools/html-entity-encode-decode/): Free online HTML entity encoder decoder. Escape HTML special characters, decode named and numeric entities, and copy the result.
- [HTML Formatter](https://candoya.com/tools/html-formatter/): Free HTML formatter to beautify HTML documents and fragments with readable indentation. Handles HTML5 structure and runs in your browser.
- [HTML Minifier](https://candoya.com/tools/html-minifier/): Free HTML minifier to compress markup, remove comments and measure exact byte savings. Preserves sensitive content and runs in your browser.
- [IPv4 Subnet Calculator](https://candoya.com/tools/ipv4-subnet-calculator/): IPv4 subnet calculator for network, broadcast, masks, usable host range, and capacity. Enter any IP with CIDR or subnet mask; results stay private.
- [ISBN Validator](https://candoya.com/tools/isbn-validator/): Free online ISBN validator for ISBN-10 and ISBN-13. Check digits, normalize hyphens, handle X and see clear invalid reasons.
- [JavaScript Beautifier](https://candoya.com/tools/js-beautifier/): Free JavaScript beautifier to format messy or minified JS online. Tune indentation, braces and line wrapping without uploading your code.
- [JSON Formatter](https://candoya.com/tools/json-formatter/): Free online JSON formatter to beautify, validate and minify JSON instantly. No sign-up, no upload - your JSON stays in your browser.
- [JSON Minifier](https://candoya.com/tools/json-minifier/): Free online JSON minifier to compress JSON to one compact line and see exactly how many bytes you saved. No sign-up, no upload - your JSON stays in your browser.
- [JSON Schema Validator](https://candoya.com/tools/json-schema-validator/): Validate JSON data against a JSON Schema online. See every failed rule with its exact data path. Free, private and no sign-up required.
- [JSON to CSV Converter](https://candoya.com/tools/json-to-csv/): Free online JSON to CSV converter. Paste a JSON array or object and get downloadable CSV instantly. Private, no upload, no sign-up.
- [JSON to XML Converter](https://candoya.com/tools/json-to-xml/): Free JSON to XML converter for nested objects, arrays and attributes. Get clean, well-formed XML instantly without uploading your data.
- [JSON to YAML Converter](https://candoya.com/tools/json-to-yaml/): Free online JSON to YAML converter. Paste JSON and get clean, block-style YAML instantly, with 2 or 4 space indent. Runs entirely in your browser.
- [JSON Validator](https://candoya.com/tools/json-validator/): Free online JSON validator to check syntax, locate errors and preview formatted JSON. No sign-up, no upload - your data stays in your browser.
- [JWT Decoder](https://candoya.com/tools/jwt-decoder/): Decode JWT tokens online to inspect headers, payload claims, expiry times and signature segments locally in your browser.
- [JWT Generator](https://candoya.com/tools/jwt-generator/): Free online JWT generator for HS256 and unsigned debug tokens. Edit header and claims locally, then copy a compact token.
- [LESS to CSS](https://candoya.com/tools/less-to-css/): LESS to CSS converter powered by Less.js. Compile variables, nesting, mixins and functions locally, then copy or download clean CSS.
- [Markdown Table Generator](https://candoya.com/tools/markdown-table-generator/): Build a Markdown table in a visual grid or convert CSV and spreadsheet data. Set column alignment, preview it live, and copy clean Markdown.
- [Markdown to HTML](https://candoya.com/tools/markdown-to-html/): Convert Markdown to HTML instantly with GitHub tables, task lists, code blocks and a safe preview. Copy or download the result without uploading text.
- [XML Formatter](https://candoya.com/tools/xml-formatter/): Free online XML formatter to beautify, validate and minify XML in your browser. No upload, no sign-up.
- [XML Minifier](https://candoya.com/tools/xml-minifier/): Free XML minifier to remove formatting whitespace and optional comments, validate structure and measure exact byte savings in your browser.
- [XML to JSON Converter](https://candoya.com/tools/xml-to-json/): Free XML to JSON converter for attributes, repeated elements, namespaces and CDATA. Get formatted JSON instantly without uploading your data.
- [YAML Formatter](https://candoya.com/tools/yaml-formatter/): Free online YAML formatter to validate and clean up YAML with comments, anchors and block strings. Runs in your browser.
- [YAML to JSON Converter](https://candoya.com/tools/yaml-to-json/): Convert YAML to JSON online with live validation, multi-document support and clean formatting. Your config stays in your browser.
- [YAML Validator](https://candoya.com/tools/yaml-validator/): Free online YAML validator to check syntax, find line and column errors, preview valid YAML and keep config text in your browser.
- [SCSS to CSS](https://candoya.com/tools/scss-to-css/): SCSS to CSS converter powered by Dart Sass. Compile variables, nesting, mixins and modules locally, then copy or download clean CSS.
- [SHA-256 Hash Generator](https://candoya.com/tools/sha-256-hash/): Free online SHA-256 hash generator. Hash any text or file to a 64-character digest instantly, as hex or Base64. No upload - runs in your browser.
- [SQL Formatter](https://candoya.com/tools/sql-formatter/): Free SQL formatter to beautify queries with dialect-aware indentation and keyword casing. Your database code stays in your browser.
- [TOML to JSON](https://candoya.com/tools/toml-to-json/): Convert TOML to JSON online with live validation, clean formatting and safe handling for dates and large integers. Your config stays in your browser.
- [URL Encode and Decode](https://candoya.com/tools/url-encode-decode/): Free online URL encoder and decoder. Convert text to percent-encoding and back instantly, with full Unicode support. No upload, runs in your browser.
- [Query String Builder](https://candoya.com/tools/query-string-builder/): Free query string builder for encoded URL parameters, arrays, blank values, and full links. Create and copy the result privately in your browser.
- [Query String Parser](https://candoya.com/tools/query-string-parser/): Free query string parser. Decode URL parameters, keep duplicate keys, edit values, and rebuild a query string or full URL in your browser.
- [Regex Tester](https://candoya.com/tools/regex-tester/): Test JavaScript regular expressions online with live matches, capture groups and replacement previews. Your patterns and text stay in your browser.
- [Screen Resolution Detector](https://candoya.com/tools/screen-resolution-detector/): Free screen resolution detector. See your screen size, viewport, device pixel ratio, orientation, color depth and browser display facts locally.
- [SVG Optimizer](https://candoya.com/tools/svg-optimizer/): Free SVG optimizer to minify vector files with SVGO, compare exact byte savings and preview the result. Files stay in your browser.
- [URL Parser](https://candoya.com/tools/url-parser/): Free online URL parser. Paste any URL to split it into scheme, host, port, path, query parameters, and fragment instantly. Runs in your browser, nothing uploaded.
- [User-Agent Parser](https://candoya.com/tools/user-agent-parser/): Parse a User-Agent string into browser, engine, OS, device, CPU, and crawler details. Free, instant, and processed in your browser.
- [UUID Generator (v4 & v7)](https://candoya.com/tools/uuid-generator/): Generate UUID v4 and time-ordered UUID v7 identifiers online. Bulk up to 1000, uppercase or no-hyphen format, one-click copy. Runs in your browser.
- [Chart Maker](https://candoya.com/tools/chart-maker/): Make bar, line, and pie charts online from your own labels and values. Customize colors, preview live, and export PNG or SVG with no sign-up.
- [CSV Editor](https://candoya.com/tools/csv-editor/): Edit CSV files online in a spreadsheet-style table. Add rows or columns, fix values, then copy or download clean CSV without uploading data.
- [CSV Filter](https://candoya.com/tools/csv-filter/): Filter CSV rows by column values, numbers, dates or booleans. Combine rules, preview matches and export a clean CSV privately in your browser.
- [CSV Column Extractor](https://candoya.com/tools/csv-column-extractor/): Extract and reorder CSV columns by heading or position. Preview, copy, and download private UTF-8 CSV while quoted cells stay intact.
- [CSV Deduplicator](https://candoya.com/tools/csv-deduplicate/): Remove duplicate rows from CSV by any column or combination. Keep the first or last match, preview changes, and download locally.
- [CSV Diff](https://candoya.com/tools/csv-diff/): Compare CSV files by a shared key and find added, removed, or changed rows. Review cell-level differences and export a private local report.
- [CSV Merger](https://candoya.com/tools/csv-merger/): Merge CSV files online by stacking rows and aligning headers. Reorder, preview, copy, and download locally with no upload or sign-up.
- [CSV Sorter](https://candoya.com/tools/csv-sorter/): Sort CSV rows by one or more columns as text, numbers, or dates. Preview, copy, and download the result privately in your browser.
- [CSV Splitter](https://candoya.com/tools/csv-splitter/): Split CSV files by row count, equal parts, or column value. Keep headers, preview every part, and download a private local ZIP without uploads.
- [CSV Statistics](https://candoya.com/tools/csv-statistics/): Calculate CSV statistics for every column, including missing values, uniques, quartiles, mean, median and standard deviation, in your browser.
- [CSV to Chart](https://candoya.com/tools/csv-to-chart/): Turn CSV into bar, line, or pie charts online. Paste or upload data, choose columns, then download SVG or PNG. Your data stays in your browser.
- [CSV to Markdown Table](https://candoya.com/tools/csv-to-markdown-table/): Convert CSV to a Markdown table with live preview, delimiter detection, alignment, safe escaping, copy, and download. Your data stays in your browser.
- [CSV to XML Converter](https://candoya.com/tools/csv-to-xml/): Free CSV to XML converter for clean, well-formed XML with custom tags and delimiters. Paste CSV, copy or download XML, all in your browser.
- [CSV Viewer](https://candoya.com/tools/csv-viewer/): Open CSV and TSV files in a clean, searchable table. Sort columns, page through rows, copy or download a filtered view, all in your browser.
- [Histogram Maker](https://candoya.com/tools/histogram-maker/): Make a histogram online from pasted numbers or a CSV column. Compare automatic bins, frequency, density, and cumulative views, then export PNG, SVG, or CSV.
- [JSON Flatten](https://candoya.com/tools/json-flatten/): Flatten nested JSON into dot-path keys instantly. Choose separators and array notation, then copy clean flat JSON. Free, private, and browser-based.
- [Pivot Table](https://candoya.com/tools/pivot-table/): Create pivot tables from CSV data instantly. Summarize rows and columns, aggregate values by sum, count, average, min or max, and export as CSV or Markdown - all in your browser.
- [SQL Playground](https://candoya.com/tools/sql-playground/): Run SQL online in a private SQLite playground with sample data, instant result tables, CSV export, and no sign-up. Everything stays in your browser.
- [SQLite Browser](https://candoya.com/tools/sqlite-browser/): Open SQLite files in a private online viewer. Browse tables and schema, run read-only SQL, and export CSV without uploading your database.
- [AES Encrypt and Decrypt](https://candoya.com/tools/aes-encrypt-decrypt/): Encrypt and decrypt text with AES-256-GCM online. Password-based, authenticated, and private in your browser with no upload or sign-up.
- [File Hash Calculator](https://candoya.com/tools/file-hash/): File hash calculator for SHA-256, SHA-512, SHA-1 and MD5 checksums. Verify any local file privately with drag and drop - no upload.
- [Caesar Cipher](https://candoya.com/tools/caesar-cipher/): Free online Caesar cipher tool. Encode and decode text with any shift (0-25), try ROT13, or brute-force all shifts to crack unknown ciphers. Runs in your browser.
- [HMAC Generator](https://candoya.com/tools/hmac-generator/): Free online HMAC generator to compute message authentication codes with SHA-1, SHA-256, SHA-384 or SHA-512. No sign-up, no download - runs in your browser.
- [IBAN Validator](https://candoya.com/tools/iban-validator/): Validate an IBAN online by country, length and MOD-97 checksum. Get clear error details while your bank number stays in your browser.
- [Passphrase Generator](https://candoya.com/tools/passphrase-generator/): Generate a secure random passphrase from EFF words. Adjust length and separators, see honest entropy, and copy it locally in your browser.
- [Password Generator](https://candoya.com/tools/password-generator/): Generate strong random passwords free online. Pick the length and symbols, see entropy and crack time, copy in one click. Runs in your browser.
- [Password Strength Meter](https://candoya.com/tools/password-strength-meter/): Check password strength with pattern-aware scoring, crack-time estimates, and useful feedback. Analysis runs locally in your browser.
- [PBKDF2 Derive](https://candoya.com/tools/pbkdf2-derive/): PBKDF2 generator to derive hex or Base64 keys from a password with configurable salt, hash, iterations and length. Runs locally in your browser.
- [Rail Fence Cipher](https://candoya.com/tools/rail-fence-cipher/): Free online rail fence cipher tool. Encrypt and decrypt text with any number of rails, see the zigzag pattern, and copy the result. Runs in your browser.
- [RSA Key Pair Generator](https://candoya.com/tools/rsa-key-pair-generator/): Generate RSA key pairs online in PEM or JWK format with 2048, 3072, or 4096-bit keys. WebCrypto runs locally, so private keys stay on your device.
- [Shamir Secret Sharing](https://candoya.com/tools/secret-sharing-shamir/): Split a secret into threshold shares with Shamir secret sharing, then recover it from any sufficient subset. Runs locally in your browser.
- [SHA-384 Hash Generator](https://candoya.com/tools/sha-384-hash/): Generate a SHA-384 hash from text or a file in your browser. Copy a 96-character hex or Base64 digest and compare checksums privately.
- [TOTP Code Generator](https://candoya.com/tools/totp-code-generator/): Generate a current TOTP or 2FA code from a Base32 secret in your browser. RFC 6238 checked, memory-only, with no upload, storage, or sign-up.
- [QR Code Generator](https://candoya.com/tools/qr-code-generator/): Free QR code generator for links and text. Download PNG or SVG, pick colors and size - runs in your browser, no sign-up, and codes never expire.

[All tools](https://candoya.com/tools/)

---

*Markdown edition of <https://candoya.com/tools/dev/>, published for AI agents and other automated readers. Index of key pages: <https://candoya.com/llms.txt>.*