---
id: kb-2026-00076
title: JWT (JSON Web Token)
schema_type: TechArticle
category: computer-science
language: en
confidence: medium
last_verified: "2026-05-30"
created_date: "2026-05-22"
generation_method: ai_structured
derived_from_human_seed: true
conflict_of_interest: none_declared
is_live_document: false
data_period: static
completeness: 0.82
atomic_facts:
  - id: fact-computer-science-jwt-001
    statement: "RFC 7519 defines JSON Web Token (JWT) as a compact, URL-safe means of representing claims between two parties."
    source_title: "RFC 7519: JSON Web Token (JWT)"
    source_url: "https://www.rfc-editor.org/rfc/rfc7519.txt"
    confidence: medium
  - id: fact-computer-science-jwt-002
    statement: "RFC 7519 describes JWT claims as a JSON object that can be used as the payload of a JSON Web Signature or as the plaintext of a JSON Web Encryption structure."
    source_title: "RFC 7519: JSON Web Token (JWT)"
    source_url: "https://www.rfc-editor.org/rfc/rfc7519.txt"
    confidence: medium
  - id: fact-computer-science-jwt-003
    statement: "RFC 8725 updates JWT deployment guidance by documenting security threats and best current practices for implementing and deploying JSON Web Tokens."
    source_title: "RFC 8725: JSON Web Token Best Current Practices"
    source_url: "https://www.rfc-editor.org/rfc/rfc8725.txt"
    confidence: medium
known_gaps:
  - "This entry explains JWT structure and security boundaries, not vendor-specific identity provider behavior."
  - "Operational token lifetimes, key rotation policies, and revocation design depend on the deployment context."
disputed_statements: []
primary_sources:
  - title: "RFC 7519: JSON Web Token (JWT)"
    authors:
      - Jones, M.
      - Bradley, J.
      - Sakimura, N.
    type: rfc
    year: 2015
    url: "https://www.rfc-editor.org/rfc/rfc7519.txt"
    institution: IETF
  - title: "RFC 8725: JSON Web Token Best Current Practices"
    authors:
      - Jones, M.
      - Sheffer, Y.
      - Hardt, D.
    type: rfc
    year: 2020
    url: "https://www.rfc-editor.org/rfc/rfc8725.txt"
    institution: IETF
secondary_sources: []
---

## TL;DR

JWT is a compact, URL-safe claims format standardized by RFC 7519. It is commonly used with JSON Web Signature or JSON Web Encryption structures, so a JWT can carry claims with integrity protection, and in some modes confidentiality, without requiring the article to assert any one authentication architecture.

## Core Explanation

A JWT represents claims as JSON. In many web systems, those claims identify a subject, issuer, audience, or expiration time, but the exact claim set is application-specific. The important boundary is that a readable JWT is not automatically encrypted: signing protects integrity, while encryption is a separate JSON Web Encryption mode.

RFC 8725 narrows the safe-use story. It treats JWTs as security-sensitive objects and documents implementation threats such as weak algorithm handling, substitution between different JWT kinds, and validation mistakes. For practical systems, the safe default is to validate issuer, audience, expiration, token type, and the expected cryptographic algorithm for the specific use case.

## Further Reading

- [RFC 7519: JSON Web Token (JWT)](https://www.rfc-editor.org/rfc/rfc7519.txt)
- [RFC 8725: JSON Web Token Best Current Practices](https://www.rfc-editor.org/rfc/rfc8725.txt)

## Related Articles

- [JWT: JSON Web Tokens - Authentication, Claims, and Security](../jwt-json-web-tokens-authentication-claims-and-security.md)
- [OAuth 2.0](../oauth2.md)
- [Semantic Web and Ontologies: Knowledge Representation, OWL Reasoning, and Linked Data](../../ai/semantic-web-ontology.md)