Fix Guides

JSON to Base64URL: encode payloads correctly (URL-safe Base64)

Ruby: Decode Base64URL to JSON safely

Opening and ending tag mismatch: causes and fixes

Java: convert Base64URL to Base64 safely

Premature end of data in tag: causes and fixes

Couldn't find end of Start Tag: causes and fixes

Comment not terminated: causes and fixes

Go: Decode Base64URL without padding (JWT-style)

Escape ''' in XML (inside URLs): correct rules and fast fixes

Empty lines in text → JSON array (no upload)

Escape apostrophes in XML attributes (correct rules)

Escape '<' in XML (in text nodes): correct rules and fast fixes

Whitespace is not allowed at this location: causes and fixes

Handle duplicate keys in JSON (no upload)

Escape '<' in XML (in embedded HTML fragments): correct rules and fast fixes

The element type must be terminated by the matching end-tag: causes and fixes

Convert query strings to JSON locally without uploading

Convert JSON to a query string locally without uploading

Escape '<' in XML (inside URLs): correct rules and fast fixes

Namespace prefix is not defined: causes and fixes

C#/.NET: Remove whitespace/newlines from Base64URL safely

Base64URL in logs: remove line breaks and sanitize before sharing

Convert large XML feeds (no upload)

Arrays from repeated XML tags (no upload)

Trim CSV values safely (no upload)

Escape ''' in XML (in embedded HTML fragments): correct rules and fast fixes

Avoid CSV formula injection (no upload)

Python: convert Base64URL to Base64 safely

XML DOCTYPE/DTD entities: how they work (and when to avoid them)

Convert Base64URL to Base64 (and back) without breaking decoding

Escape '&' in XML (inside URLs): correct rules and fast fixes

Base64URL padding: why '=' is missing (and when to add it back)

No-upload INI: handoff template for frontend teams

Escape '&' in XML (in attributes): correct rules and fast fixes

Node.js: convert Base64URL to Base64 safely

Go: Decode Base64URL to JSON safely

Escape '&' in XML (in embedded HTML fragments): correct rules and fast fixes

C#/.NET: decode Base64URL correctly (URL alphabet + padding)

Decode Base64URL online safely: avoid uploading tokens

Escape '&' in XML (in text nodes): correct rules and fast fixes

No-upload .env: handoff template for frontend teams

No-upload .env: handoff template for DevOps teams

Python: Token redaction before sharing Base64URL samples

Rust: decode Base64URL (JWT) safely

JavaScript: convert Base64URL to Base64 safely

No-upload XML: handoff template for frontend teams

No-upload XML: handoff template for support teams

Escape '"' in XML (in text nodes): correct rules and fast fixes

Rust: convert Base64URL to Base64 safely

Java: decode Base64URL correctly (use URL decoder, not standard Base64)

The reference to entity must end with the ';' delimiter: causes and fixes

Ruby: Token redaction before sharing Base64URL samples

C#/.NET: convert Base64URL to Base64 safely

Escape '"' in XML (inside URLs): correct rules and fast fixes

PHP: Decode Base64URL to JSON safely

Node.js: decode Base64URL (JWT) safely

No-upload .env: handoff template for data teams

PHP: decode Base64URL (JWT) safely

Go: decode Base64URL (JWT) safely

Rust: Token redaction before sharing Base64URL samples

Reliability checks for Base64URL flows in access tokens

Reliability checks for Base64URL flows in refresh tokens

No-upload XML: handoff template for DevOps teams

Ruby: convert Base64URL to Base64 safely

Rust: Safe JWT signature segment inspection (without false verification claims)

PHP: Base64URL in API middleware

Reliability checks for Base64URL flows in ID tokens

Ruby: Safe JWT signature segment inspection (without false verification claims)

Ruby: decode Base64URL (JWT) safely

Reliability checks for Base64URL flows in OAuth tokens

Go: Base64URL in API middleware

Java: Convert Base64URL to text safely (UTF-8)

C#/.NET: Convert Base64URL to bytes safely

Node.js: Convert Base64URL to text safely (UTF-8)

C#/.NET: Base64URL in API middleware

Ruby: Base64URL in API middleware

C#/.NET: Token redaction before sharing Base64URL samples

Node.js: Token redaction before sharing Base64URL samples

No-upload JSON: handoff template for data teams

Base64URL in batch jobs: compatibility matrix

Base64URL in CDN cache keys: failure modes

Python: Decode Base64URL without padding (JWT-style)

Java: Token redaction before sharing Base64URL samples

Go: Building reliable Base64URL test fixtures

Ruby: Add '=' padding to Base64URL safely

Deduplicate text → JSON array (no upload)

Reliability checks for Base64URL flows in email links

C#/.NET: Decode Base64URL without padding (JWT-style)

Reliability checks for Base64URL flows in browser logs

Rust: Convert Base64URL to text safely (UTF-8)

Java: Observability checks for Base64URL pipelines

Base64URL in reverse proxies: normalization steps

JavaScript: encode Base64URL correctly

Java: decode Base64URL (JWT) safely

No-upload Base64/URL/JWT: handoff template for support teams

Base64URL in OIDC flows: normalization steps

Rust: Convert Base64URL to bytes safely

No-upload .properties: handoff template for frontend teams

Java: Safe JWT signature segment inspection (without false verification claims)

Java: Building reliable Base64URL test fixtures

PHP: Token redaction before sharing Base64URL samples

Ruby: Convert Base64URL to text safely (UTF-8)

Base64URL in telemetry pipelines: compatibility matrix

Go: Convert Base64URL to text safely (UTF-8)

No-upload YAML: handoff template for DevOps teams

Rust: Base64URL in API middleware

Python: Observability checks for Base64URL pipelines

Java: Convert Base64URL to bytes safely

Python: decode Base64URL (JWT) safely

C#/.NET: decode Base64URL (JWT) safely

Base64URL in OAuth flows: failure modes

C#/.NET: Convert Base64URL to text safely (UTF-8)

No-upload .env: handoff template for backend teams

Go: Add '=' padding to Base64URL safely

Java: Base64URL in API middleware

No-upload INI: handoff template for DevOps teams

Node.js: Observability checks for Base64URL pipelines

Go: Observability checks for Base64URL pipelines

Base64URL in event streams: normalization steps

XML entity handling in Android manifests: prevention guardrails