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💻Developer Tools

JSON, encoding, regex, hashing, network debugging, config generators and more developer tools, running locally.

93 tools tagged "Developer"

{}JSON FormatterFree online JSON formatter: beautify or minify, validate with the exact line and column of any error, browse a collapsible tree, sort keys and escape strings.🔤Base64 Encode/DecodeFree online Base64 encoder and decoder: UTF-8 safe, optional URL-safe variant, convert text to Base64 and back in real time. Processed locally, never uploaded.🔗URL Encode/DecodeFree online URL encoder and decoder with encodeURIComponent and encodeURI modes. Escapes Chinese, spaces and special characters. Real-time and local, no upload.🎫JWT DecoderFree online JWT decoder: decode the header and payload of a JSON Web Token, show expiry and issued-at times, all locally without uploading the token.🕐Timestamp ConverterFree online Unix timestamp converter: convert timestamps and dates, auto-detect seconds or milliseconds, and show local, UTC, ISO 8601 and relative time.#️⃣Hash / ChecksumFree online hash calculator: SHA-1, SHA-256, SHA-384 and SHA-512 of text or any file through the browser crypto API. Files never leave your device.🆔UUID GeneratorFree online UUID generator: create RFC 4122 UUID v4 in bulk with a cryptographic RNG. Options for uppercase, no hyphens and braces, with one-click copy.🔢Base ConverterFree online number base converter: convert between binary, octal, decimal, hexadecimal and any base 2–36. Uses BigInt for huge integers, computed locally.🔍Regex TesterFree online regular expression tester: match and highlight as you type, list capture groups and support the g/i/m/s/u flags. Runs locally, nothing uploaded.🆚Text DiffFree online text diff tool: compare two texts line by line, highlight added and removed lines, and optionally ignore case and trailing spaces. Runs locally.🎨Color ConverterFree online color converter: convert between HEX, RGB and HSL with a built-in color picker and preview, one-click copy, computed locally in real time.🔣HTML Entity Encode/DecodeFree online HTML entity encoder and decoder: escape < > & " and more to entities or decode them back, with optional non-ASCII conversion. Runs locally.⏰Cron ExpressionFree online cron tool: parse a 5-field cron (min hour dom mon dow), break down each field and predict the next 5 run times in your local zone. Computed locally.📰Markdown PreviewFree online Markdown previewer: render Markdown to a live web preview with GFM, tables and code blocks, copy the generated HTML. Runs locally, no upload.🔐Chmod CalculatorFree online chmod calculator: tick read, write and execute for owner, group and others to convert octal (755) and symbolic (rwxr-xr-x), with setuid and sticky.🌐Subnet CalculatorFree online IPv4 subnet calculator: enter 192.168.1.10/24 for the network, broadcast, host range and count, wildcard mask, binary view and a prefix table.🧾CSV to JSONFree online CSV ⇄ JSON converter: handles quotes, commas and newlines inside fields, auto-detects the delimiter, with a header toggle and type conversion.🚦HTTP Status CodesComplete HTTP status code reference: every 1xx–5xx code with its name and a plain-language explanation, searchable by code, name or keyword.🔷JSON to TypeScriptFree online JSON to TypeScript converter: interfaces or types from JSON, nested objects split into named interfaces, optional fields inferred, Go structs too.📋Markdown Table GeneratorFree online Markdown table generator: edit cells visually, add rows and columns, set per-column alignment, and import from Excel, CSV, TSV or Markdown.🗃️SQL FormatterFree online SQL formatter: beautify SELECT, JOIN, subqueries, CASE and WITH with clause line breaks and indentation, set keyword case, or minify to one line.🈶Unicode ConverterFree online Unicode converter: text to and from \uXXXX, HTML entities, UTF-8 hex bytes, %XX and U+ code points, with correct emoji handling and auto-detection.🧭URL ParserFree online URL parser: split a link into protocol, host, port, path and hash, edit decoded query parameters in a table, rebuild the URL live, export as JSON.🕵️User-Agent ParserFree online User-Agent parser: browser and version, rendering engine, OS, device type and model, and bot detection for Googlebot, Bingbot and GPTBot.🔣Truth Table GeneratorFree online truth table generator: enter a Boolean or propositional expression for the full table, tautology check, canonical DNF/CNF and Quine–McCluskey.🎨CSS FormatterFree online CSS beautifier and minifier: one declaration per line, correct @media, nesting and url() handling, optional property sorting and a byte count.🔀JSON DiffFree online JSON diff: compare two documents ignoring key order, see added, removed and changed paths with old and new values, and export an RFC 6902 patch.🏷️XML FormatterFree online XML formatter: beautify or minify XML, validate it with line and column errors, keep comments and CDATA, and convert XML to JSON and back.📋YAML to JSON ConverterFree online YAML and JSON converter: multi-document YAML, anchors, aliases and merge keys, errors with line and column, plus indent, sorting and folding.🌈CSS Gradient GeneratorFree online CSS gradient generator: build linear, radial and conic gradients visually with draggable stops, an angle dial and presets. Copy CSS or export PNG.🌓CSS Box Shadow GeneratorFree online CSS shadow generator for box-shadow and text-shadow: stack layers with offset, blur, spread and colour, start from presets, copy CSS or Tailwind.🌀curl ConverterFree online curl converter: paste a curl command and get fetch, axios, Node, Python requests, Go, PHP or Java code, plus a parsed view of the request.🔒Text Encryption & DecryptionFree online text encryption: AES-256-GCM or CBC with a password (PBKDF2, OpenSSL-compatible output), raw key + IV mode, RSA-OAEP and HMAC signatures.🗺️JSONPath TesterFree online JSONPath tester: query JSON with $.store.book[*], recursive .., slices and filters, listing every matching path and value, plus a cheat sheet.🏗️HTML FormatterFree online HTML formatter: beautify or minify in one click, keep <pre> and <textarea> intact, format embedded CSS and JSON-LD, with a sandboxed live preview.🔏JWT Generator & SignerFree online JWT generator: edit the header and payload, sign with HS, RS, PS or ES 256/384/512, make RSA / EC key pairs, and verify with exp/nbf checks locally.🎹Keycode FinderFree online JavaScript key event viewer: press a key to see event.key, code, keyCode, location and modifiers, with an on-screen keyboard and a reference table.🧪Mock Data GeneratorFree online mock data generator: define fields and generate up to 10,000 rows of fake names, emails, addresses, dates and IDs, exported as JSON, CSV or SQL.🔌WebSocket TesterFree online WebSocket client: connect to ws:// or wss://, send text, JSON or binary messages, read a filterable log, auto-reconnect, plus an SSE tester.🚫.gitignore GeneratorFree .gitignore generator: combine 40 templates (Node, Python, Java, Go, Rust, Unity, macOS, VS Code…), dedupe, add custom rules, test which paths git ignores.🟨JavaScript FormatterFree online JavaScript formatter: beautify or minify JS, TypeScript, JSX and JSON with 2/4-space or tab indent and line width. Handles regex, templates, ASI.✅JSON Schema Generator & ValidatorGenerate a draft 2020-12 or draft-07 JSON Schema from sample JSON (types, required, nesting, formats) and validate JSON with JSON Pointer error paths. Free.🪧Meta Tag GeneratorFree SEO meta tag generator & checker: title, description, canonical, robots, Open Graph, Twitter cards, hreflang, JSON-LD, with Google and social previews.🐳docker run ↔ Compose ConverterConvert docker run to docker-compose.yml and back: ports, volumes, env, networks, healthchecks, limits, logging and GPUs, plus warnings for unsupported flags.📮HTTP Request TesterFree online HTTP client: send GET, POST, PUT or DELETE with params, headers, JSON, form or file bodies and auth, then inspect status, timing, headers and body.🟢Nginx Config GeneratorGenerate Nginx configs for static sites, SPAs, reverse proxies, WebSocket and PHP-FPM with HTTPS, HTTP/2, gzip, caching, security headers and rate limits.🧶String Escape / UnescapeEscape or unescape strings for JSON, JavaScript, Java, C#, C, Go, Python, SQL, bash, regex, CSV, XML and URL, with every changed character highlighted.🪶SVG OptimizerOptimize SVGs online: strip editor data and unused defs, compact path data, compare previews side by side, batch ZIP download, Data URI and React JSX export.🔆Color Contrast CheckerCheck color contrast: WCAG 2.x ratio and APCA Lc, AA/AAA pass or fail for text and UI, nearest passing color, color-blindness preview and palette matrix.📟Multi-Encoding ConverterConvert text, hex or files to Base32, Base58Check, Base62, Base36, Ascii85, Z85, binary, Quoted-Printable, Punycode and more, with auto-detection on decode.🛤️Regex VisualizerVisualize JavaScript regexes as railroad diagrams with a plain-language breakdown of groups, quantifiers, classes and lookarounds. Export SVG or PNG.📦Semver ToolsSemver tools: validate SemVer 2.0.0, compare and sort versions, bump like npm version, and test npm ranges (^, ~, x-ranges, ||) with plain explanations.🧂Bcrypt Generator & CheckerGenerate and verify password hashes online: bcrypt (cost 4–14, $2a/$2b/$2y), Argon2id, scrypt and PBKDF2, auto-detecting PHP, Django, Flask and passlib formats.🛂SSL Certificate DecoderDecode SSL/TLS certificates online: subject, issuer, days to expiry, SANs, key usage, OCSP/CRL, SCTs and SHA-256 fingerprints, with chain and signature checks.🧑‍💻Code ScreenshotTurn code into beautiful images: auto-detected syntax highlighting, 10 themes, macOS window, line numbers, gradient backgrounds, PNG up to 4x or SVG.♻️HTML to Markdown ConverterConvert HTML to Markdown and back: headings, nested lists, task lists, GFM tables, code blocks, links and images. Paste rich text from web pages or Docs.🗝️TOTP GeneratorGenerate and verify TOTP / HOTP 2FA codes from a Base32 secret or otpauth:// URI. SHA1/256/512, 6–8 digits, custom period, countdown, new secrets and QR codes.⚙️Config File ConverterConvert config files between JSON, YAML, TOML, INI, .env and Java .properties. Auto-detects the format, full TOML 1.0 support, errors with line numbers.🔶CSS clip-path GeneratorVisual CSS clip-path maker: drag polygon points or use circle, ellipse and rounded inset. 25 presets (arrow, star, speech bubble) previewed on your image.🍱Flexbox & Grid PlaygroundInteractive Flexbox and CSS Grid playground: tweak container and item properties live, drag to name grid-template-areas, and copy CSS, HTML or Tailwind classes.🤖robots.txt & Sitemap GeneratorBuild robots.txt (block GPTBot, ClaudeBot and other AI bots in one click), test URLs with Google’s rules, and generate or validate sitemap.xml.🟪Tailwind Color Palette GeneratorTurn a brand color into a Tailwind-style 50–950 scale on the default palette’s OKLCH curve, with contrast badges and v3, v4, CSS, SCSS and JSON export.🚪Htpasswd GeneratorGenerate .htpasswd entries with bcrypt, APR1-MD5, SHA-512/256 crypt or {SHA}, merge into existing files, verify passwords and get nginx / .htaccess config.🛰️IPv6 CalculatorFree IPv6 toolkit: RFC 5952 compress/expand, prefix ranges, paged subnetting, address types (Teredo, 6to4, NAT64), EUI-64, ip6.arpa and random ULA.🛢️JSON to SQL ConverterConvert JSON arrays or CSV to SQL: inferred types and primary key, CREATE TABLE, batched INSERT and UPSERT for MySQL, PostgreSQL, SQLite, SQL Server, Oracle.🛎️OpenAPI ViewerView OpenAPI 3.x and Swagger 2.0 (JSON/YAML) online: tag-grouped endpoints, search, $ref schema trees, example JSON, curl/fetch snippets and HTML export.🖇️ASCII Table GeneratorTurn CSV, spreadsheet cells or Markdown into text tables: ASCII, Unicode boxes, Markdown, reST, Org-mode, MySQL style, HTML or LaTeX, CJK-aligned.🔑Classical Cipher LabEncode and decode Caesar/ROT13, Vigenère (with Kasiski auto-crack), Playfair, rail fence, affine, Bacon and substitution ciphers, plus an Enigma I simulator.💾Protobuf, MessagePack, CBOR & BSON DecoderDecode raw Protobuf without a schema or with a pasted .proto, plus MessagePack, CBOR and BSON. Tree + JSON views with byte-offset highlighting.🔦Hex ViewerView any file as hex + ASCII: go to offsets, search bytes or text, decode values, detect 60+ file types, parse PNG/ZIP/PDF/ELF/PE headers and diff files.🦺HTTP Security Headers CheckerPaste raw HTTP response headers to get an A+ to F grade with checks for HSTS, CSP, X-Frame-Options, cookies, CORS and more, plus fixes and a CSP builder.🚥Sorting Algorithm VisualizerWatch 14 sorting algorithms animate: bubble, insertion, shell, merge, quick, heap, counting, radix, bucket and Timsort, with counters, step mode and races.🌳XPath & CSS Selector TesterTest XPath 1.0 and CSS selectors on XML or HTML: live highlighting, namespace prefixes, function results and shortest unique selectors for any clicked node.☸️Kubernetes YAML GeneratorGenerate Kubernetes manifests: Deployment/StatefulSet, Service, Ingress, ConfigMap, Secret, HPA, PVC and CronJob, with validation and docker run/compose import.©️Open Source License PickerAnswer a few questions to choose an open source license, compare 15 licenses side by side, and generate a filled-in LICENSE, SPDX headers and manifest fields.💠SSH Key GeneratorGenerate SSH key pairs in your browser: Ed25519, RSA 2048/3072/4096 or ECDSA, with OpenSSH keys, passphrases, PKCS#8, fingerprints and randomart.🐧systemd Unit GeneratorGenerate systemd .service and .timer files with restart, dependencies and hardening explained; convert cron to OnCalendar, preview next runs, lint units.💫CSS Animation GeneratorBuild CSS @keyframes animations visually: 18 presets, a keyframe timeline, cubic-bezier and steps() easing, live preview, and copy CSS or Tailwind config.🧿GraphQL FormatterFormat, minify and validate GraphQL queries and SDL: syntax errors with line and column, unused variables and fragments, curl and fetch snippets, a type graph.🍭Color Palette GeneratorPress space for new color palettes, lock favorites, use OKLCH harmonies or image colors, check contrast and color blindness, export CSS, Tailwind, ASE.🌊SVG Wave & Shape GeneratorGenerate SVG decorations: layered waves, random blobs, dot, hex and topographic patterns, layered peaks; gradients and seeds; export SVG, PNG, CSS or React.🪣SQL on CSVRun SQL on CSV, TSV and JSON files in your browser: type inference, WHERE, GROUP BY, aggregates, JOINs, CASE, subqueries and functions; export CSV or JSON.👻Invisible Character DetectorDetect and remove zero-width characters, bidi controls (Trojan Source), non-breaking spaces, soft hyphens, control chars, homoglyphs and full-width letters.🐙JSON Graph VisualizerTurn JSON, YAML or CSV into a node graph: objects and arrays as cards linked by edges, with zoom, pan, collapse, search, JSONPath and PNG/SVG export.✅File ChecksumFree online checksum tool: compute MD5, SHA-1, SHA-256 and CRC32 for several files at once, compare against a published value and handle multi-GB files.🛢️SQLite BrowserFree online SQLite browser: inspect tables, row counts and indexes, run real SQL in a genuine SQLite engine, export CSV / JSON or download the new .sqlite.📇MIME typesFree MIME type lookup: search 80+ common formats by extension or type, copy the Content-Type with one click, with notes on charset and download headers.🔌Port numbersFree port number lookup: search 60+ common ports by number, service or purpose, see which must never face the internet, and find what is using one locally.🌿Git commandsFree Git cheat sheet: 60+ commands grouped by what you want to do — undo, branch, rebase, remotes, history, stash, cleanup — with copy and danger warnings.📜Commit messageFree Conventional Commits generator: pick a type, fill in the summary and get a correct header, BREAKING CHANGE footer and a ready-to-paste git commit command.⚙️.editorconfigFree .editorconfig generator: choose indentation, line endings, charset and trailing-space rules, start from a project preset, and get the exceptions added.🔢Bitwise CalculatorFree online bitwise calculator: AND, OR, XOR, NOT, shifts and rotates at 8, 16, 32 or 64 bits, with two's complement reading, clickable bits, hex and decimal.🔤ASCII TableFree online ASCII table: codes 0-127 in decimal, hex, octal, binary and escape form, every control character explained, Latin-1 128-255 and a code point lookup.