The one rule for this entire pillar
None of these tools are for secrecy. Base64 is encoding, not encryption. JWT decoding shows you claims but proves nothing. MD5 and SHA hashes are fast by design, exactly what you don't want for passwords. If you need actual secrecy or authentication, use:
- For passwords: bcrypt, argon2id, or scrypt. Never a fast hash.
- For secrecy: AES-GCM or equivalent AEAD via WebCrypto / libsodium. Not in a web form.
- For auth tokens: generate and verify server-side with a real JWT library, never trust a decoded JWT as authenticated.
Why these tools live together
Encoding and inspection utilities share a security posture: they handle inputs that are sometimes sensitive (tokens, API keys, personal data). That's why every tool in this pillar runs 100% in your browser, no server, no log files, no request trails. Open DevTools → Network and paste a token: zero requests.
They also share a workflow. Devs don't use just one of them, they chain:
- Decode a JWT → inspect the payload → spot an ID that looks like a hash → verify in the Hash Generator.
- Receive a
data:URL → strip to pure Base64 → decode → save somewhere. - Build a URL with query params → percent-encode the values → smoke-test the whole URL.
- Generate UUIDs for test fixtures → use them as idempotency keys in real requests.
Standards these tools follow
- Base64: RFC 4648 (standard + URL-safe variants)
- URL encoding: RFC 3986 + application/x-www-form-urlencoded
- JWT: RFC 7519 (claims), RFC 7515 (signing / JWS)
- Hashes: FIPS 180-4 for SHA-1/SHA-2 family, RFC 1321 for MD5
- UUIDs: RFC 9562 (supersedes 4122); v4 and v7 supported
All 19 tools in this category
- QR Code Generator: Generate QR codes for URLs, text, Wi-Fi, contact cards. Custom size, colors, error correction. Download as PNG or SVG. 100% client-side.
- Barcode Generator: Generate Code 128, Code 39, EAN-13, UPC-A, EAN-8 and ITF barcodes as SVG with automatic check digit calculation.
- Morse Code Translator: Translate text to Morse code and Morse back to English, live. Play it as audio at any speed, with a full alphabet chart.
- Password Generator: Generate strong random passwords with configurable length, character classes, and exclusions. Real entropy meter, crack-time estimate, bulk mode.
- Base64 Encoder / Decoder: Encode and decode Base64 strings and files. Client-side, safe for sensitive data.
- ROT13 / Caesar Cipher: Encode and decode ROT13 and arbitrary Caesar shifts. Letter frequency analysis. 100% client-side.
- Binary to Text Converter: Translate binary to text and text to binary, hex, decimal or octal, both ways, live. Full UTF-8 and emoji support with a per-character table.
- UPC Generator: Enter 11 or 12 digits to generate a scannable UPC-A barcode with computed check digit and full breakdown.
- URL Encoder / Decoder: Percent-encode and decode URLs per RFC 3986.
- UUID Generator: Generate UUID v4 and v7 identifiers in bulk.
- JWT Decoder: Decode and inspect JSON Web Tokens. Local-only, tokens never leave your browser.
- NATO Phonetic Alphabet Translator: Translate any text into NATO phonetic spelling for clear radio and phone communication.
- Atbash Cipher: Encode or decode text using the atbash cipher by reversing the alphabet, running entirely in your browser.
- Hash Generator: Generate MD5, SHA-1, SHA-256, and SHA-512 hashes client-side.
- Letters to Numbers (A1Z26): Convert letters to numbers (A=1, B=2) and numbers back to letters with this free A1Z26 tool.
- Hex to Text Converter: Paste a hexadecimal string to decode it into readable plain text, supporting spaces, commas, and UTF-8 characters.
- Binary to Hex Converter: Convert binary strings to hexadecimal and hex values back to binary with this free browser-based tool.
- Code 128 Barcode Generator: Encode text and numbers into a Code 128 barcode SVG with automatic code set B and C switching.
- Code 39 Barcode Generator: Create Code 39 barcodes as SVG with optional modulo 43 check digit, adjustable height and human-readable text.
Further reading
Other categories
- Data & Format: JSON, XML, YAML, CSV, SQL, HTML and Markdown: format, view, convert and diff.
- Dev Productivity: Regex, cron, timestamps, subnets, validators and everyday developer utilities.
- Frontend & Design: CSS generators, color tools, image tools, favicons and px to rem.
- Text Tools: Counters, case converters, cleaners, formatters and everyday text utilities.
- Fonts & Symbols: Fancy text, text effects, copy and paste symbols, emoticons and special characters.
- Name Generators: Names for people, pets, bands, teams, businesses, characters and usernames.
- Random & Games: Random pickers, dice, coin flips, wheels, party games and test data generators.
- Math Calculators: Algebra, fractions, factors, exponents, logarithms and everyday arithmetic.
- Geometry: Area, perimeter, volume and surface area of shapes, plus triangles and coordinates.
- Statistics & Probability: Averages, deviation, distributions, hypothesis tests, probability and combinatorics.
- Finance: Loans, interest, investing, margins, taxes, salary and business calculators.
- Health & Fitness: BMI, calories, macros, heart rate, hydration and training calculators.
- Date & Time: Dates, durations, ages, business days, calendars and time arithmetic.
- Science & Engineering: Physics, chemistry and electrical formulas with the working shown.
- Construction & DIY: Concrete, paint, flooring, roofing, lumber and home improvement estimators.
- Education & Grades: Grade, GPA and exam calculators and study helpers.
- Length & Distance: Convert meters, feet, inches, miles, kilometers and every other length unit.
- Weight & Volume: Convert kilograms, pounds, ounces, liters, gallons, cups and cooking measures.
- Temperature, Speed & Data: Temperature, speed, pressure, energy, power and digital storage converters.