Developer

Developer tools: encode, decode, format, inspect

Every developer tool on OpenTools. Base64, UUIDs, timestamps, regex, hashes and formatters, all running locally in your browser tab.

All 98 of them are listed below. Each one runs inside this tab, so nothing you open or type is uploaded — see the proof.

• .dockerignore generatorGenerate a conservative Docker build-context ignore file.
• .gitignore generatorGenerate ignore rules from reviewed built-in ecosystem presets.
• Base64 decoderDecode standard Base64 into validated UTF-8 text.
• Base64 encoderEncode Unicode text as standard Base64 in this tab.
• Base64 text decoderTurn standard Base64 back into readable text. Whitespace is ignored, the padding must be correct, and decoded bytes are rejected if they are not valid UTF-8.
• Base64 text encoderEncode text as standard Base64 with plus, slash and equals padding. Accented letters, emoji and other non-ASCII characters are read as UTF-8 bytes first.
• Base64URL text decoderTurn URL-safe Base64 back into text. The hyphen and underscore alphabet is accepted with or without padding, and non-UTF-8 byte sequences are reported.
• Base64URL text encoderEncode UTF-8 text with URL-safe Base64 and no padding.
• Binary bytes to textDecode eight-bit binary groups with strict UTF-8 validation.
• Binary calculatorAdd, subtract, multiply, divide, or take the remainder of binary integers.
• Bitwise calculatorApply AND, OR, XOR, shift, or NOT to BigInt integers.
• CIDR calculatorParse an IPv4 CIDR block and calculate its exact address range.
• Code points to textCreate text from hexadecimal Unicode scalar values.
• Cookie parserParse a Cookie request header into decoded name/value pairs.
• Cron expression builderBuild a validated five-field cron expression from explicit fields.
• Cron expression generator & translatorParse, build, and translate 5-field crontab schedules into plain English with next run estimates.
• Cron expression parserValidate and explain the five fields of a standard five-part cron expression.
• cURL to code converterConvert a cURL command line into idiomatic JavaScript fetch, Axios, Python requests, Go, Node.js, and PHP code.
• Docker & Compose generator & cheatsheetGenerate multi-container docker-compose.yml templates and essential container management CLI commands.
• EditorConfig generatorBuild a root EditorConfig with explicit indentation and line-ending choices.
• Epoch calculatorConvert ISO date-time, Unix seconds, or Unix milliseconds.
• ER Diagram to SQL ConverterTurn a Mermaid erDiagram into runnable CREATE TABLE statements for PostgreSQL, MySQL or SQLite, with primary keys, foreign keys and junction tables for many-to-many.
• Escape-sequence viewerList JavaScript-style control, quote, slash, and Unicode escapes without evaluating code.
• Full URL decoderDecode percent escapes across a whole web address while leaving reserved separators such as %26 and %3F encoded, so the structure of the link is unchanged.
• Full URL encoderEncode unsafe characters while preserving URL separators.
• Git emergency scenarios ("Flight Rules")Quick copy-paste solutions for common Git mistakes, branch recovery, and commit operations.
• GraphQL formatterIndent a bounded GraphQL document with string- and comment-aware lexical formatting.
• GraphQL variable builderValidate that GraphQL variables are a JSON object and format them.
• HAR (HTTP Archive) SanitizerSanitize .har network capture files by stripping cookies, authorization headers, and sensitive query tokens before sharing.
• HEX to HSLConvert a CSS hexadecimal color to rounded HSL values.
• HEX to RGBConvert 3, 4, 6, or 8 digit CSS hexadecimal colors to RGBA.
• Hexadecimal to textDecode even-length hexadecimal with strict UTF-8 validation.
• HMAC generatorCalculate a keyed HMAC for UTF-8 text through Web Crypto.
• HSL to HEXConvert hue, saturation, lightness, and optional alpha to HEX.
• HTML entity decoderDecode the five core named entities and numeric entities.
• HTML entity encoderEscape ampersands, angle brackets, quotes, and apostrophes.
• HTTP header parserParse header lines into a case-normalized JSON object without making a request.
• HTTP status codes referenceSearchable encyclopedia of 1xx–5xx HTTP response status codes with RFC definitions and API guidance.
• INI viewerParse a bounded INI subset into a section-preserving JSON object.
• IPv4 address converterConvert an IPv4 dotted address to unsigned decimal, hexadecimal, and binary.
• IPv4 subnet calculatorCalculate network, broadcast, mask, usable range, and host capacity.
• IPv6 subnet calculatorParse an IPv6 address and calculate the normalized network and final address for a prefix.
• JSON diffCompare two parsed JSON values and list changed paths.
• JSON editorValidate and normalize edited JSON with two-space indentation.
• JSON formatterValidate JSON and format it with two-space indentation.
• JSON key sorterRecursively sort object keys while preserving array order.
• JSON minifierValidate JSON and remove insignificant whitespace.
• JSON path testerResolve a bounded JSON path using property and array-index notation.
• JSON string escaperEscape text for the inside of a JSON string literal.
• JSON string unescaperDecode JSON string escapes without evaluating code.
• JSON to TypeScript & JSON Schema converterInfer strict TypeScript interface, type alias, or JSON Schema Draft-07 definitions from parsed JSON objects.
• JSON to Zod Schema GeneratorGenerate strict, type-safe TypeScript Zod validation schemas (z.object, z.string().email(), z.number().int(), z.array(), z.infer) directly from JSON data.
• JWT decoder & inspectorDecode and inspect compact JWT header, payload, signature presence, and time claims without verification.
• JWT inspectorDecode the header and payload locally without trusting them.
• LLM Secret & API Key ScrubberRedact API keys, AWS credentials, tokens, connection strings, emails, and passwords before pasting prompts into ChatGPT or Claude.
• Mock & dummy data generatorGenerate structured realistic mock dataset records for testing databases and APIs in JSON, CSV, or SQL.
• Nano ID generatorGenerate URL-safe random identifiers using browser cryptographic randomness.
• Number-base converterConvert signed integers between bases 2 through 36 with BigInt precision.
• OpenAPI example generatorGenerate one JSON example from a bounded object schema subset.
• OpenAPI viewerInspect a JSON OpenAPI document and list declared HTTP operations.
• package.json inspectorInspect package identity, module type, scripts, dependencies, and engines.
• Password generatorGenerate passwords with secure randomness and an explicit character preset.
• Random token generatorGenerate cryptographically random bytes as hexadecimal or Base64URL.
• Regex explainerValidate a JavaScript regular expression and annotate its common tokens in source order.
• Regex extractorPull one capture group out of every regular-expression match and list the results one per line, up to 200 matches, with group 0 returning the whole match.
• Regex replacerReplace text with JavaScript replacement tokens such as $& and $1.
• Regular-expression testerList bounded JavaScript regex matches and capture groups.
• Remove query parameterRemove every instance of one parameter from an absolute URL.
• RGB to HEXConvert integer RGB channels and optional alpha to CSS hexadecimal.
• Semantic-version calculatorValidate a SemVer core version and calculate its next major, minor, or patch.
• Set query parameterSet or replace one query parameter on an absolute URL.
• SHA-256 text hashHash text with SHA-256 and read back the 64-character hexadecimal digest, the usual choice for fingerprints, cache keys and integrity comparisons.
• SHA-384 text hashHash text with SHA-384 and read back the 96-character hexadecimal digest, used where a longer truncated SHA-2 value is required by a spec or a vendor.
• SHA-512 text hashHash text with SHA-512 and read back the 128-character hexadecimal digest, the longest SHA-2 option, often asked for in signing and archival workflows.
• SQL formatterFormat a bounded SQL statement using quote- and comment-aware tokenization.
• SQL minifierRemove comments and unnecessary whitespace with quote-aware SQL tokenization.
• SQL parameter previewReplace positional ? markers with safely quoted display literals from a JSON array.
• SQL PII Obfuscator & SanitizerMask sensitive customer emails, credit cards, and phone numbers in SQL queries and data dumps for safe debugging.
• SQL Schema to Visual ER DiagramCreate an ER diagram from SQL DDL online. Export interactive visual SVG, Mermaid erDiagram, DBML, and PlantUML in your browser with zero server uploads.
• SVG cleaner & optimizerRemove XML declarations, comments, editor metadata, and redundant whitespace from SVG markup.
• Text checksum calculatorCalculate a SHA-256, SHA-384 or SHA-512 checksum of pasted text in your browser and read it as lowercase hexadecimal to compare with a published value.
• Text to binary bytesTurn text into eight-bit binary, one space-separated group per UTF-8 byte. Useful for teaching how characters map to bytes or for checking a binary dump.
• Text to hexadecimalTurn text into lowercase hexadecimal, two digits for each UTF-8 byte and no separators, for when you need to see how characters such as emoji are stored.
• ULID generatorGenerate one Crockford Base32 ULID from the current time and secure randomness.
• Unicode code-point inspectorList Unicode scalar values by user-perceived character.
• Unix chmod & permissions calculatorCalculate POSIX file permissions, convert octal to symbolic modes, and generate exact chmod commands.
• Unix timestamp converterConvert Unix seconds, milliseconds, and ISO dates.
• URL component decoderDecode one percent-encoded component; plus signs stay plus.
• URL component encoderPercent-encode one query value or path segment so that spaces, ampersands, slashes and question marks survive being placed inside a larger web address.
• URL origin extractorReturn the protocol, hostname, and effective port origin.
• URL parserInspect the standard components of an absolute URL.
• URL path segmentsList the path segments of a web address as a JSON array. Empty segments are dropped and each remaining one is percent-decoded, so %20 reads as a space.
• User-agent parserIdentify common browser engine, operating-system family, and mobile hints.
• UTF-8 byte counterCount Unicode characters, UTF-16 code units, and UTF-8 bytes.
• UTF-8 byte decoderDecode decimal bytes with strict UTF-8 validation.
• UTF-8 byte encoderShow UTF-8 bytes as space-separated decimal values.
• UUID generatorGenerate cryptographically random UUID v4 values.
• Webhook payload inspectorValidate a pasted JSON payload and summarize its local structure.