🛠️ Developer Tools
Formateador JSON, codificador de URL, generador de hash y más
Embelece, valida y formatea JSON. Embelecedor, validador e impresor JSON gratuitos.
Abrir herramienta →Codifica o decodifica cadenas de URL. Herramienta gratuita de codificador y decodificador de URL.
Abrir herramienta →Genera hashes SHA-1, SHA-256, SHA-512 y MD5 en línea.
Abrir herramienta →Genera contraseñas fuertes, seguras y aleatorias bajo demanda.
Abrir herramienta →Prueba y depura expresiones regulares con coincidencia en tiempo real y grupos de captura.
Abrir herramienta →Genera identificadores UUID v4 aleatorios. Genera hasta 100 UUID en lote.
Abrir herramienta →Convierte marcas de tiempo Unix a fechas y viceversa. Convertidor de época con soporte de zona horaria.
Abrir herramienta →Construye y explica expresiones de horario cron visualmente. Ve los próximos tiempos de ejecución.
Abrir herramienta →Minifica HTML, CSS y JavaScript. Ve los ahorros de tamaño al instante.
Abrir herramienta →Calcula notación CIDR, dirección de red, broadcast y rangos de hosts.
Abrir herramienta →Crea gradientes CSS con un editor visual. Copia el código CSS.
Abrir herramienta →Crea sombras CSS visualmente con vista previa en vivo. Copia el código.
Abrir herramienta →Convierte entre binario, decimal, octal y hexadecimal.
Abrir herramienta →Convierte entre bytes, KB, MB, GB, TB y más tamaños de datos.
Abrir herramienta →Decodifica e inspecciona JSON Web Tokens. Ver header, payload y firma.
Abrir herramienta →Compara dos textos lado a lado y ve las diferencias resaltadas.
Abrir herramienta →The utilities you reach for a dozen times a day and never want to think about — formatting a blob of JSON, decoding a token to see why auth is failing, generating a UUID, working out what a cron expression actually means.
All of them run in your browser. That is the point: pasting a production JWT, an internal API response or a customer record into a random web form is a habit worth breaking, and here there is no server to send it to. Open the network tab and check.
Which tool do I want?
| If you… | Use |
|---|---|
| You have unreadable JSON and want it formatted or validated | Formateador JSON |
| Auth is failing and you need to see what is in the token | Decodificador JWT |
| You are writing a pattern and want to test it live | Probador de expresión regular |
| You need a strong password or an API key | Generador de contraseña |
| A cron line is opaque and you want it in English | Generador de expresión Cron |
| You are planning subnets or checking whether an IP is in range | Calculadora de subredes |
| You have a Unix timestamp and need a date | Convertidor de marca de tiempo |
| You want to see exactly what changed between two files | Comparar textos / Diff |
Decoding a JWT is not verifying it
The JWT decoder here shows you the header and payload, because both are plain base64url — anyone holding the token can read them. What it does not do is check the signature, and that distinction has caused real security incidents.
A decoded token showing admin: true tells you what the token claims, not whether that claim is true. Verification means recomputing the signature with the issuer's key and confirming it matches, then checking the expiry, the issuer and the audience. That has to happen on your server, with a library, every time.
So: never put secrets in a JWT payload, since it is readable by design. And never trust a claim you have only decoded. The decoder is a debugging aid for working out why auth is behaving oddly — it is not an authorisation check.