FOR DEVS/ TOOLS

Developer Tools

Thirty-five single-page browser tools that run entirely on your machine. No analytics on these pages, no requests to a backend on submit, no telemetry. Bookmark them, use them offline, paste them in incognito tabs. Every tool below loads in under 200ms and respects your time. Full index also at /tools.

ENCODERS & DECODERS/ 5 TOOLS

Base64Encode and decode strings or files. Round-trip safe, supports binary upload, copy with one click.EncodingFiles Hex ConverterTwo-way between bytes, integers, ASCII, and color hex. Useful for debugging binary protocols and CSS.EncodingColor URL EncoderPercent-encode and decode query strings, paths, and fragments. Handles unicode, plus-vs-space variants.WebEncoding HTML EntitiesEncode and decode & < > and 250+ named/numeric entities. For XSS-safe output and email templates.WebEncoding JWT DecoderDecode JWTs, inspect header/payload/signature, check expiry. Decoder runs locally, never leaves your browser.AuthSecurity

DATA FORMATS/ 3 TOOLS

JSON FormatterPretty-print, validate, collapse, jq-style queries. Handles 50MB inputs without hanging.DataValidation YAML ConverterYAML to JSON and back, validation, syntax highlight. Catches indent errors and tab/space mixes.DataConfig Markdown PreviewLive render, GitHub-flavored, copy HTML output. Tables, fenced code, task lists all supported.WebWriting

GENERATORS/ 6 TOOLS

UUID Generatorv1, v4, v7, batch mode. Lowercase or upper, with or without hyphens. Bulk export to CSV.GeneratorDatabase Password GeneratorLength, charset, entropy meter, copy. Generated client-side, never transmitted.SecurityGenerator Hash GeneratorMD5, SHA-1, SHA-256, SHA-512. For checksums, integrity verification, and quick fingerprinting.SecurityGenerator Lorem IpsumWords, sentences, paragraphs at custom length. Plus a "hacker ipsum" mode for prototype copy.GeneratorDesign QR GeneratorText, URL, contact card, downloadable PNG/SVG. All sizes, error correction levels, no watermark.GeneratorMobile SSH Key GeneratorEd25519 or RSA 2048/3072/4096 keypairs in OpenSSH format. WebCrypto-backed, generated locally, never transmitted.SecurityGenerator

TIME, DATE & PATTERN MATCHING/ 4 TOOLS

Unix TimestampConvert seconds, milliseconds, ISO 8601 across timezones. Live clock for sanity-checking servers.TimeConversion Cron DecoderParse expressions, show next 10 fire times in your timezone. Handles step values, ranges, lists.DevOpsScheduling Regex TesterLive match, capture groups, common patterns library. Saves the last 10 patterns to localStorage.PatternValidation Diff ViewerSide-by-side or unified, line and char diff. Useful for config audits and copy-paste comparisons.ComparisonPattern

NETWORK & HTTP/ 3 TOOLS

API TesterMini Postman, GET, POST, PUT, DELETE, custom headers, JSON body. Saves history locally.HTTPTesting HTTP Status CodesEvery status code with explanation, common causes, RFC link. Includes 418 (teapot) and 451 (legal).HTTPReference Common PortsService-to-port reference, well-known and registered. Quick lookup for firewall and load-balancer config.NetworkReference

SYSTEM & WEB/ 2 TOOLS

Chmod CalculatorSymbolic and numeric Unix permissions. Click bits to compose, paste a mode to decompose.UnixPermissions Color ConverterHEX, RGB, HSL, CSS variables, palettes. Eyedropper for the screen, contrast ratio for accessibility.DesignWeb

STRING UTILITIES/ 4 TOOLS

Slug GeneratorConvert text to URL-safe slug. Handles unicode, accents, German umlauts, emoji.StringURL Case ConvertercamelCase, snake_case, kebab-case, PascalCase, CONSTANT_CASE, dot.case, Title, Sentence.StringNaming Text StatsChar, word, line, sentence, paragraph counts. Reading and speaking time. Tweet capacity.StringWriting Markdown TableVisual table builder. Paste TSV or CSV, set alignment, copy clean Markdown.MarkdownWriting

IMAGE & CRYPTO SIGNATURES/ 2 TOOLS

Image to Base64Drag-drop image, get a data URI plus HTML, CSS, and Markdown snippets.ImageEncoding HMAC GeneratorHMAC-SHA1/256/384/512 with any secret. Hex, base64, base64url. For webhook signature verification.SecurityWebhook

DATA CONVERSION & QUERY/ 4 TOOLS

CSV ↔ JSONTwo-way converter. Header-aware, quoted-value safe, array of objects or array of arrays output.DataConversion JSONPath TesterLive JSONPath query evaluator. Supports $, ., [n], [*], .. recursive descent.JSONQuery Curl to CodePaste curl, get JavaScript fetch, Python requests, and Node axios equivalents.HTTPConversion JSON to TypesPaste JSON, get TypeScript interfaces, Go structs, Pydantic models, and Rust serde structs.TypesCodegen

CRYPTO CONVERTERS/ 2 TOOLS

Gwei ConverterWei, Gwei, Ether, gas-cost calculator. Live ETH price for USD conversion.CryptoEthereum Satoshi ConverterSats, BTC, USD live conversion. Useful for invoices, micropayments, and Lightning channels.CryptoBitcoin