Weekend Projects Easy 9,900/mo

JWT Decoder and Debugger

Decode, verify, and debug JSON Web Tokens in the browser. Paste a JWT, see header and payload, verify signature — without sending your token to any server.

DeveloperSecurity
MRR Potential
$1K–$4K
Time to MVP
1 weekend
Search Volume
9,900/mo
Market Size
$300M

The Problem

jwt.io sends tokens to the server which is a security risk. Decoding JWTs manually requires Base64 parsing. No tool validates expiry, issuer, and audience claims easily. Teams need a client-side JWT debugger.

The Solution

Client-side JWT decoder that runs entirely in the browser — decode, inspect, and verify JWTs without your tokens ever leaving your machine.

Target Audience

Backend developers debugging auth tokens, security engineers auditing JWT implementations, and DevOps teams troubleshooting API authentication

Key Features

1
Client-side only: tokens never leave the browser (zero-trust)
2
Header and payload decoding with syntax highlighting
3
Signature verification for HS256, RS256, ES256, and more
4
Claim validation: exp, nbf, iss, aud, and custom claims
5
Token comparison for debugging auth changes between environments
6
Shareable decoded view (metadata only, no sensitive data)

Market Opportunity

Market Size
$300M — Authentication and developer tools
Monthly Searches
9,900/mo
MRR Potential
$1K–$4K
Why Now?

JWT is the standard for API auth. Security concerns about sharing tokens with third parties. Client-side tools build trust. API auth debugging is a daily developer task.

Revenue Model

Free: unlimited decoding. Pro: $3/mo (team workspace + API + claim templates + no ads). Annual: 20% discount.

Competitive Landscape

jwt.io

JWT debugger. Free, sends tokens to server, basic validation

jwt.ms (Microsoft)

JWT decoder. Free, basic, limited validation

Browser DevTools

Can decode Base64, no JWT-specific features

Custom decode scripts

Per-project, no UI, no signature verification

Recommended Tech Stack

Next.jsjose library (client-side)VercelStripe

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