Tool Guides
In-depth reference articles for every tool in SmartDevBox — what each tool does, how to read its output fields, worked examples, and answers to common questions. All tools run 100% in your browser; no data is ever sent to a server.
Encoding & Decoding
- Base64 DecoderDecode any Base64 string back to plain text instantly in your browser. Free, no sign-up, 100% client-side. Supports standard and URL-safe Base64.
- Base64 EncoderEncode any text or string to Base64 instantly in your browser. Free, no sign-up, 100% client-side. Results copy with one click.
- JWT DecoderDecode JWT tokens and inspect header, payload, and signature instantly. Free, no sign-up. Works without the signing secret. 100% client-side.
- JWT EncoderCreate and sign JWT tokens using HMAC HS256, HS384, or HS512 in your browser. Free, no sign-up, 100% client-side.
- URL EncoderPercent-encode any string for safe use in URLs instantly in your browser. Free, no sign-up, 100% client-side.
- URL DecoderDecode any percent-encoded URL string back to readable text instantly in your browser. Free, no sign-up, 100% client-side.
- URL ParserParse any URL into its protocol, host, path, query parameters, and hash fragment instantly. Free, no sign-up, 100% client-side.
- HTML EncoderConvert special characters like < > & " to HTML entities instantly in your browser. Free, no sign-up, 100% client-side.
- HTML DecoderConvert HTML entities like & < > back to their original characters instantly. Free, no sign-up, 100% client-side.
- Hex to ASCII ConverterConvert hexadecimal byte strings to ASCII text instantly in your browser. Free, no sign-up, 100% client-side.
- ASCII to Hex ConverterConvert ASCII text to hexadecimal representation instantly in your browser. Free, no sign-up, 100% client-side.
- Base32 EncoderEncode any text to Base32 (RFC 4648) in your browser. Free, no sign-up, 100% client-side.
- Base32 DecoderDecode Base32-encoded strings back to plain text instantly. Free, no sign-up, 100% client-side.
- Backslash EscapeEscape newlines, tabs, and special characters with backslash sequences in your browser. Free, no sign-up.
- Backslash UnescapeConvert backslash-escaped sequences like \n and \t back to actual characters. Free, no sign-up, 100% client-side.
- ROT13 Encoder/DecoderEncode or decode text using the ROT13 cipher instantly in your browser. Free, no sign-up, 100% client-side.
- ROT47 Encoder/DecoderEncode or decode text using the ROT47 cipher (full printable ASCII range) in your browser. Free, no sign-up.
- Base64 Image DecoderDecode a Base64 image data URI and view MIME type, byte size, and HTML/CSS usage examples. Free, no sign-up.
- UUID to Hex ConverterConvert between standard UUID format and 32-character hex strings instantly. Free, no sign-up, 100% client-side.
Formatting
- JSON FormatterFormat and pretty-print JSON instantly in your browser. Validates syntax and shows error location. Free, no sign-up, 100% client-side.
- JSON ValidatorValidate JSON and get exact error location (line and column) instantly. Free, no sign-up, 100% client-side.
- XML FormatterFormat and indent XML markup instantly in your browser. Validates structure. Free, no sign-up, 100% client-side.
- XML MinifierMinify XML by removing all unnecessary whitespace. Free, no sign-up, 100% client-side.
- SQL FormatterFormat and beautify SQL queries with proper indentation and keyword casing. Free, no sign-up, 100% client-side.
- CSS FormatterFormat and beautify CSS stylesheets with consistent indentation. Powered by Prettier. Free, no sign-up, 100% client-side.
- CSS MinifierMinify CSS by removing comments, whitespace, and redundant semicolons. Free, no sign-up, 100% client-side.
- HTML FormatterFormat and indent HTML markup with consistent indentation. Powered by Prettier. Free, no sign-up, 100% client-side.
- JavaScript FormatterFormat JavaScript and TypeScript code with Prettier. Consistent style in one paste. Free, no sign-up, 100% client-side.
- JavaScript MinifierMinify JavaScript by removing comments and whitespace. Free, no sign-up, 100% client-side.
- JavaScript ValidatorValidate JavaScript syntax and report errors instantly in your browser. Free, no sign-up, 100% client-side.
- Date FormatterFormat any date or timestamp across 12 locales and 4 date styles. Free, no sign-up, 100% client-side.
Conversion
- Markdown PreviewLive split-pane Markdown editor with side-by-side rendered HTML preview. Free, no sign-up, 100% client-side.
- JSON to CSV ConverterConvert JSON arrays of objects to CSV format instantly in your browser. Free, no sign-up, 100% client-side.
- JSON to TSV ConverterConvert JSON arrays to TSV (tab-separated values) format instantly. Free, no sign-up, 100% client-side.
- JSON to YAML ConverterConvert JSON to YAML format instantly in your browser. Free, no sign-up, 100% client-side.
- YAML to JSON ConverterConvert YAML to JSON format instantly in your browser. Free, no sign-up, 100% client-side.
- CSV to JSON ConverterConvert CSV data to a JSON array of objects instantly. Headers become keys. Free, no sign-up, 100% client-side.
- XML to JSON ConverterConvert XML to JSON format instantly in your browser. Preserves attributes and nesting. Free, no sign-up.
- JSON to XML ConverterConvert JSON to XML format instantly in your browser. Free, no sign-up, 100% client-side.
- Markdown to HTML ConverterConvert Markdown text to HTML instantly in your browser. Free, no sign-up, 100% client-side.
- HTML to TextStrip HTML tags and extract plain readable text from HTML. Free, no sign-up, 100% client-side.
- HTML to JSX ConverterConvert HTML markup to React-compatible JSX syntax instantly. Handles className, inline styles, and void elements. Free, no sign-up.
- Color ConverterConvert colors between HEX, RGB, HSL, and HSV instantly in your browser. Free, no sign-up, 100% client-side.
- Number Base ConverterConvert integers between binary, octal, decimal, and hexadecimal instantly. Free, no sign-up, 100% client-side.
- Unix Timestamp ConverterConvert Unix timestamps to human-readable dates and times, and vice versa. Free, no sign-up, 100% client-side.
- Seconds to H:M:S ConverterConvert a total number of seconds to hours:minutes:seconds format. Free, no sign-up, 100% client-side.
- H:M:S to Seconds ConverterConvert H:M:S time format to total seconds. Free, no sign-up, 100% client-side.
- Decimal to Roman Numeral ConverterConvert any integer between 1 and 3999 to Roman numerals. Free, no sign-up, 100% client-side.
- Roman Numeral to Decimal ConverterConvert Roman numerals to decimal integers. Free, no sign-up, 100% client-side.
Other
- JSON EscapeEscape a string for safe embedding inside a JSON value. Handles quotes, newlines, and backslashes. Free, no sign-up.
- JSON UnescapeConvert JSON-escaped strings back to normal text. Free, no sign-up, 100% client-side.
Generation
- UUID GeneratorGenerate cryptographically random UUID v4 identifiers instantly. Bulk generation supported. Free, no sign-up, 100% client-side.
- ULID GeneratorGenerate Universally Unique Lexicographically Sortable Identifiers (ULIDs). Free, no sign-up, 100% client-side.
- Hash GeneratorCompute MD5, SHA-1, SHA-256, and SHA-512 hashes for any text. Free, no sign-up, 100% client-side.
- Random String GeneratorGenerate random strings with configurable length and character set. Free, no sign-up, 100% client-side.
- Password GeneratorGenerate strong random passwords with configurable length, uppercase, digits, and symbols. Free, no sign-up.
- Lorem Ipsum GeneratorGenerate Lorem Ipsum placeholder text by word, sentence, or paragraph count. Free, no sign-up, 100% client-side.
- QR Code GeneratorGenerate QR codes from any URL or text. Download as PNG. Free, no sign-up, 100% client-side.
- Random Number GeneratorGenerate random integers or decimals within a custom range. Free, no sign-up, 100% client-side.
- Random IP GeneratorGenerate random IPv4 addresses for testing and development. Free, no sign-up, 100% client-side.
- Random MAC Address GeneratorGenerate random locally-administered MAC addresses for testing. Free, no sign-up, 100% client-side.
Inspection
- Regex TesterTest regular expressions against any input text. See matches and positions. Free, no sign-up, 100% client-side.
- JSONPath EvaluatorEvaluate JSONPath expressions against JSON input and view matching nodes. Free, no sign-up, 100% client-side.
- String InspectorView character, word, line, sentence, byte, and Unicode statistics for any text. Free, no sign-up, 100% client-side.
- Cron Job ParserParse and explain cron expressions in plain English with next scheduled run times. Free, no sign-up, 100% client-side.
- X.509 Certificate DecoderDecode PEM-encoded X.509 certificates: subject, issuer, validity dates, serial, and signature algorithm. Free, no sign-up, 100% client-side.
- HTML PreviewLive preview HTML markup in a sandboxed iframe alongside the source editor. Free, no sign-up, 100% client-side.
More from SmartDevBox
SmartDevBox vs Alternatives
- SmartDevBox vs CyberChefHow auto-detection compares to CyberChef's recipe model.
- SmartDevBox vs jwt.ioA single-purpose JWT decoder vs a 91-tool all-in-one toolkit.
- SmartDevBox vs base64decode.orgWhy a dedicated Base64 site is no longer necessary.
Developer Glossary
- What is Base64 encoding?Binary-to-text encoding used in email, HTTP, and data URIs.
- What is a JWT?Compact, self-contained token for transmitting authentication claims.
- What is JSON?Lightweight text format for structured data.
- What is XML?Hierarchical markup language for structured data interchange.
- What is a Unix timestamp?Seconds elapsed since 1970-01-01 UTC — the universal time representation.
- What is a hash function?One-way function mapping any input to a fixed-length digest.
- What is a URL?Address of a resource on the internet: scheme, host, path, query, fragment.
- What is a UUID?128-bit identifier formatted as 8-4-4-4-12 hex groups.
- What is a cron expression?Five-field string that schedules recurring tasks in Unix-like systems.
- What is a regex?Pattern language for matching, searching, and extracting text.
- What is an X.509 certificate?Signed document binding a public key to an identity — the foundation of HTTPS.
- What is CSV?Plain-text tabular format with comma-separated fields.
- What is SQL?Standard language for querying and managing relational databases.
- What is YAML?Human-readable, indentation-based data serialisation format.
- What is a color code?HEX, RGB, or HSL notation that uniquely identifies a color.