https://jsokit.com/blog/tags/base64/ Recent content in Base64 on JsonKit Blog Hugo en © 2025 JsonKit Wed, 11 Mar 2026 17:55:24 +0000 https://jsokit.com/blog/posts/building-a-jwt-debugger-in-the-browser-base64url-decoding-and-signature-verification/ Wed, 11 Mar 2026 17:55:24 +0000 https://jsokit.com/blog/posts/building-a-jwt-debugger-in-the-browser-base64url-decoding-and-signature-verification/ Building a JWT Debugger in the Browser: Base64URL Decoding and Signature Verification If you’re a backend developer, you’ve probably pasted a JWT into jwt.io more times than you can count. But have you ever thought about what happens behind the scenes when you hit that “decode” button? Let’s walk through building one from scratch. The Three-Part JWT Structure A JWT looks like this: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9. eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIn0. SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c Three dot-separated segments: Header, Payload, Signature. https://jsokit.com/blog/posts/image-to-base64-conversion-a-deep-dive-into-filereader-api-and-data-url-implementation/ Fri, 20 Feb 2026 10:06:49 +0000 https://jsokit.com/blog/posts/image-to-base64-conversion-a-deep-dive-into-filereader-api-and-data-url-implementation/ Image to Base64 Conversion: A Deep Dive into FileReader API and Data URL Implementation I recently worked on an image upload feature that needed preview and Base64 conversion. Thought it was just calling an API, but ended up hitting several walls—memory overflow with large files, cross-origin image loading failures, MIME type misidentification… So I decided to document the complete implementation approach. The Essence of Base64 Encoding Base64 isn’t encryption—it’s encoding. It transforms binary data into printable ASCII characters, making it safe to transmit over text-based protocols (HTTP, JSON, XML). https://jsokit.com/blog/posts/building-a-code-sharing-tool-url-hash-storage-and-base64-encoding-techniques/ Fri, 30 Jan 2026 15:09:21 +0000 https://jsokit.com/blog/posts/building-a-code-sharing-tool-url-hash-storage-and-base64-encoding-techniques/ Building a Code Sharing Tool: URL Hash Storage and Base64 Encoding Techniques Recently, I built a code sharing tool that requires a “no backend, permanent validity” sharing mechanism. After researching several approaches, I chose URL Hash + Base64 encoding - simple and reliable. Why URL Hash Storage? Traditional code sharing tools use two approaches: Backend database storage - Store code in database, generate short links. Pros: short links. Cons: needs backend, storage cost, links can expire. https://jsokit.com/blog/posts/base64-encodingdecoding-from-btoa-to-full-unicode-support/ Sat, 24 Jan 2026 15:39:10 +0000 https://jsokit.com/blog/posts/base64-encodingdecoding-from-btoa-to-full-unicode-support/ Base64 Encoding/Decoding: From btoa to Full Unicode Support I recently worked on a project requiring safe text data transmission, and Base64 encoding was unavoidable. While I’ve used it countless times, implementing a reliable tool revealed some interesting details worth sharing. What is Base64? Simply put, Base64 is a method to represent binary data using 64 printable characters: Uppercase letters A-Z (26 characters) Lowercase letters a-z (26 characters) Digits 0-9 (10 characters) + and / (2 characters) Plus = for padding at the end.