Security Tools
Decode and inspect JWT tokens, and encode or decode Base64 strings — directly in your browser, no signup, no upload, no install. Break a JWT into its header, payload, and signature with human-readable timestamps, or convert text to and from Base64 in one click. Every operation runs entirely on your device, so tokens and data stay private and results appear instantly.
JWT Decoder
Decode and inspect JWT tokens instantly. View the header, payload, and signature.
Open JWT DecoderBase64 Encoder & Decoder
Encode text to Base64 or decode Base64 back to plain text, instantly, in one tool.
Open Base64 Encoder & DecoderSecurity Tools - When to use ?
Two focused tools, each built for a specific step in debugging tokens and encoded data.
JWT Decoder
Decode and inspect JWT tokens instantly. View the header, payload, and signature.
You're debugging an authentication flow and need to see exactly what claims are inside a JWT — a user ID, a role, or an expiry — without writing code.
- Splits a token into header, payload, and signature
- iat/exp/nbf claims shown with readable dates
- Clear that signature verification is not performed
- Copy any section with one click
Base64 Encoder & Decoder
Encode text to Base64 or decode Base64 back to plain text, instantly, in one tool.
You need to embed binary-safe text in a URL, config file, or API payload, or decode a Base64 string someone sent you back into readable text.
- One-click toggle between encode and decode
- Carries output over as input when switching modes
- Handles Unicode text, not just ASCII
- Clear error message for malformed Base64 input
Everything You Need to Debug Tokens & Encoded Data
A consistent toolkit for the security tasks developers reach for most often — all free, all client-side.
Fast Browser Processing
Every operation runs locally in JavaScript — no round trip to a server.
Data Never Leaves Your Browser
Tokens and strings are processed on-device and never uploaded anywhere.
Decode JWT Tokens
Inspect the header, payload, and signature of any JSON Web Token.
Readable Timestamps
iat, exp, and nbf claims are automatically converted to human-readable dates.
Encode & Decode Base64
Convert text to Base64 or Base64 back to plain text instantly.
Round-Trip Friendly
Switch between encode and decode without retyping your input.
No Signature Verification Claims
Clear about what these tools do and don’t check, so you never over-trust a result.
Copy Result
Copy decoded or encoded output to your clipboard in one click.
JWTs, Base64, and Why They Need Tooling
Modern web applications constantly pass around encoded and token-based data — session tokens, API keys, authorization headers — and being able to quickly inspect that data is a routine part of debugging authentication and integration issues without waiting on backend logs or a debugger.
A JSON Web Token (JWT) is a compact, URL-safe way to represent claims between two parties. It has three Base64Url-encoded parts separated by dots: a header describing the signing algorithm, a payload containing the actual claims, and a signature that proves the token hasn’t been tampered with — provided you have the secret or public key to verify it.
Base64 is a much simpler mechanism: an encoding scheme that represents binary data as printable ASCII text using 64 characters. It is not encryption and provides no confidentiality — it exists purely to let binary-unsafe systems (like text-based protocols, URLs, or JSON strings) carry arbitrary bytes safely.
Developers reach for tools like these because a JWT payload is only readable once decoded, and Base64 data is unreadable until converted back to text — a formatter or decoder turns an opaque token or string into something you can actually verify at a glance, without spinning up a script for a one-off check.
Where JWTs & Base64 Are Used
Tokens and encoded strings show up across authentication and API integrations.
API Authentication
Bearer tokens in Authorization headers are usually JWTs.
Single Sign-On
OAuth 2.0 and OpenID Connect flows issue JWTs as access and ID tokens.
Session Management
Stateless sessions stored as signed tokens instead of server-side sessions.
Cloud IAM
Cloud providers issue and validate JWTs for service-to-service auth.
Webhooks & APIs
Base64 encodes binary payloads and credentials in text-based requests.
Config & Env Files
Base64 is used to safely embed binary or multiline values as text.
A Typical Debugging Workflow
How these tools fit together when you're debugging a real authentication issue.
- 1
Receive a Token or String
Copy a JWT from an Authorization header, or a Base64 string from an API.
- 2
Decode the JWT
Inspect the header and payload claims.
- 3
Check Expiry & Claims
Confirm exp, iat, and custom claims match what you expect.
- 4
Encode / Decode Base64
Convert any binary-safe text payload as needed.
- 5
Copy Result
Grab the decoded claims or converted string for your debugging.
Try It Yourself
Sample values you can paste directly into either tool above.
Why PayloadTools?
Browser Processing
Every tool runs client-side, entirely on your device.
No Server Upload
Your tokens and data are never transmitted to or stored on a server.
Fast
Results appear instantly, with no network round trip.
Free Forever
No paywalls, tiers, or usage limits.
Mobile Friendly
Fully usable on phones and tablets, not just desktop.
Unlimited Usage
No account, no rate limits, no watermarks.
Modern UI
A clean, fast interface built for daily developer use.
Frequently Asked Questions
Common questions about JWTs, Base64, and about these tools specifically.
Related Security Resources
In-depth guides on JWTs and Base64, coming soon.
JWT vs Session Cookies
How token-based auth compares to traditional server-side sessions.
Understanding JWT Claims
A reference for standard and custom JWT payload fields.
Base64 vs Encryption
Why encoding is not a substitute for real security.
Common JWT Mistakes
Pitfalls like storing secrets in the payload or skipping expiry checks.
OAuth 2.0 and OpenID Connect
Where JWTs fit into modern authentication and authorization flows.
How to Verify a JWT Signature
What’s needed server-side to actually validate a token.