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WebUtilsLab Encoding Tools

Free Local-First Encoding Tools

Encode, decode, inspect, and generate values used in URLs, APIs, tokens, checksums, and test fixtures. Built for API clients, auth debugging, callback URLs, file checksums, identifiers, and Base64URL/JWT workflows.

Encoding tools

Encoding

URL Encoder / Decoder

Encode URL components, decode percent-encoded text, and inspect query parameters locally.

  • Component and full URL modes
  • Query parameter parser
Open URL Encoder
Encoding

URL Query Parser

Parse URL query strings locally into decoded parameters, duplicate values, UTM fields, and copy-ready JSON.

  • Decoded parameter table
  • Copy-ready JSON output
Open URL Query Parser
Encoding

UUID Generator

Generate v4 UUIDs locally, copy or download lists, and validate UUID format for developer fixtures.

  • Batch v4 UUID generation
  • Format validation and download
Open UUID Generator
Encoding

Base64 Encoder / Decoder

Encode and decode UTF-8 text, switch to URL-safe Base64, and convert small local files to Base64.

  • UTF-8 and URL-safe Base64
  • Small local file conversion
Open Base64 Encoder
Encoding

JWT Decoder

Decode JWT header and payload locally, inspect claims, and remember that decoding does not verify signatures.

  • Header and payload JSON
  • Claim and expiration summary
Open JWT Decoder
Encoding

Hash Generator

Generate SHA-256, SHA-384, SHA-512, and SHA-1 hashes locally for text or small files.

  • SHA text and file hashing
  • Hex or Base64 digest output
Open Hash Generator

Recommended encoding workflow

Best starting tool: JWT Decoder — Start here when debugging auth tokens, encoded claims, or API authorization failures.

Common workflow path: JWT Decoder Timestamp Converter Base64 Encoder / Decoder URL Query Parser

Common problem solved: Inspect token claims, read exp and iat timestamps, decode Base64URL-style values, and review callback parameters without sending pasted token text to a backend.

  1. Decode URLs, Base64 text, or JWT payloads locally before pasting values into tickets or documentation.
  2. Use Hash Generator and UUID Generator when you need copy-ready identifiers or checksums for fixtures and release checks.
  3. Move decoded JSON into JSON Formatter or Timestamp Converter when claims or payloads need deeper inspection.

Related categories

Move between related WebUtilsLab tool categories when a task crosses formats, encoding, scheduling, or implementation checks.

Data Developer Utilities Time

When to use these Encoding tools

URL and query inspection

Decode callback URLs, OAuth redirects, UTM strings, and encoded query parameters before sharing or debugging them.

Token inspection

Decode JWT and Base64URL segments locally, then move JSON claims into formatter or timestamp tools.

Checksums and IDs

Generate UUIDs and hash digests for fixtures, release checks, cache keys, or lightweight integrity comparisons.

Specific value lookups

Open the explained encoding example that matches the value you are checking.

JWT exp claim JWT iat claim

Encoding tools FAQ

Does JWT Decoder verify signatures?

No. JWT Decoder reads the header and payload locally. Decoding is not the same as cryptographic signature verification.

Do encoding tools save tokens or pasted strings?

No. These tools are designed to process pasted input in the current browser page without saving it to WebUtilsLab.

When should I use URL-safe Base64?

Use URL-safe Base64 when encoded values must travel in URLs, JWT segments, or filenames without plus signs or slashes.