🛠️ Developer toolbox
Format, validate, convert and debug JSON, YAML, SQL, JWTs, regex, cron, URLs and more, right in your browser.
All Developer toolbox tools
JSON formatter
Pretty-print JSON, optionally sorting keys.
🛠️JSON minifier
Remove all whitespace from JSON.
🛠️JSON validator
Check whether text is valid JSON and report the error.
🛠️JSON to CSV
Convert a JSON array of objects to CSV (nested keys flattened with dots).
🛠️XML formatter
Validate and pretty-print XML.
🛠️XML minifier
Strip whitespace between XML tags.
🛠️HTML formatter
Beautify HTML.
🛠️CSS formatter
Beautify CSS.
🛠️JavaScript formatter
Beautify JavaScript.
🛠️CSS minifier
Minify CSS.
🛠️HTML minifier
Collapse whitespace and drop comments in HTML (does not touch <pre>/<script> contents).
🛠️JavaScript minifier
Minify and mangle JavaScript with Terser.
🛠️SQL formatter
Format SQL for several dialects.
🛠️YAML formatter
Validate and re-indent YAML.
🛠️TOML formatter
Validate and normalise TOML.
🛠️JSON / YAML / TOML converter
Convert between JSON, YAML and TOML.
🛠️Text / code diff
Compare two texts line-by-line, word-by-word or char-by-char; returns parts and a unified patch.
🛠️Folder-content diff
Compare two sets of files ({path, content}); the Next.js app can read a dropped folder in the browser and send its text files here.
🛠️Regex tester & explainer
Run a JavaScript regex against text (sandboxed with a timeout) and get a token-by-token explanation.
🛠️Base64 / URL / HTML / Unicode encoder & decoder
Encode or decode text with base64, base64url, url, html, unicode (\uXXXX) or hex.
🛠️JWT viewer / decoder
Decode a JWT header and payload. Optionally check an HS256 signature if you supply the secret. Decoding is not verification.
🛠️UUID generator
Generate random v4 UUIDs.
🛠️Hash / HMAC generator
MD5, SHA-1, SHA-256, SHA-384, SHA-512 hashes, or HMAC when a key is given.
🛠️Test data generator
Generate fake rows. Field types: name, firstName, lastName, email, username, phone, address, city, country, company, uuid, int, float, bool, date, datetime, text, ipv4, url.
🛠️Cron expression explainer
Plain-English description plus the next run times.
🛠️Timestamp / Unix time / timezone converter
Accepts Unix seconds, milliseconds or a date string (blank = now) and shows it in any timezones.
🛠️Markdown to sanitized HTML
Render Markdown to HTML (scripts and unsafe attributes stripped) for the live preview.
🛠️SQL query builder
Build a parameterised SELECT from structured input.
🛠️SQL sample-data generator
Generate INSERT statements with fake data.
🛠️URL parser
Break a URL into protocol, host, port, path, query parameters and hash.
🛠️HTTP status code lookup
Search HTTP status codes by number or keyword (e.g. 404, redirect, timeout). Leave blank to list them all.
🛠️JSON to TypeScript
Generate TypeScript interfaces or types from a JSON sample. Merges array items and marks inconsistent keys optional.
🛠️JSON diff
Compare two JSON documents structurally and list every added, removed and changed path.
🛠️JSONPath tester
Query JSON with JSONPath: $.store.book[0].title, $.items[*].id, $..price, $['odd key'].
🛠️Number base converter
Convert integers between binary, octal, decimal, hex and any base from 2 to 36. Handles very large numbers.
🛠️chmod calculator
Convert Unix permissions between octal (755) and symbolic (rwxr-xr-x) and see the chmod command.
🛠️Meta tags & Open Graph generator
Create SEO, Open Graph and Twitter Card tags for a page, with length warnings.
🛠️robots.txt & sitemap.xml generator
Generate a robots.txt and an XML sitemap from your site URL and a list of paths.
About developer toolbox tools
Whether you are debugging an API response, checking a token or tidying a config file, these developer tools save you a trip to the terminal. Toolsera has 38 tools in this category, including JSON formatter, JSON minifier, JSON validator, JSON to CSV. All of them are free, need no account, and delete uploaded files automatically after processing.
Frequently asked questions
Are the developer toolbox tools free?
Yes. Every tool in this category is free to use and needs no sign-up.
Are my files and results private?
Uploaded files are deleted automatically after processing and results are never stored.
What can I do with developer toolbox tools on Toolsera?
Format, validate, convert and debug JSON, YAML, SQL, JWTs, regex, cron, URLs and more, right in your browser. There are 38 tools in this category, including JSON formatter, JSON minifier, JSON validator, JSON to CSV.