Base64 encode converts text into an ASCII-safe string for transport in JSON, headers, and config files. SWEDevTools: Prism encodes locally in your browser (no server), supports UTF-8 input, and can output URL-safe Base64 (base64url) for token and URL contexts. Paste your text, enable URL Safe when needed, and click Run to get deterministic output you can use in test fixtures, API calls, or documentation. Because SWEDevTools: Prism is local-first, offline-capable as a PWA, and pipeline-oriented, you can chain Base64 encoding into URL Encode, hashing, or compression steps without switching tools or exposing data to third-party websites. This is ideal for quick local debugging and repeatable pipelines across dev, staging, and production.
No. It is reversible encoding, not encryption.
That is padding. URL-safe mode commonly removes it.
A URL-safe variant using “-” and “_” instead of “+” and “/”.
Yes—encode the JSON string. Format JSON first if you need stable whitespace.
No. SWEDevTools: Prism encodes locally in your browser.
Yes for standard Base64; URL Safe matches common base64url behavior.
Transporting bytes through text-only channels like JSON, headers, and env vars.
Yes. Install the PWA and encode Base64 without internet.
Yes. You can drag and drop or upload binary files such as images, PDFs, and fonts, and the encoder will convert their raw bytes into a Base64 string. This is useful for embedding assets directly in HTML, CSS, or JSON without separate file hosting.
Base64 encoding increases data size by approximately 33 percent because every three bytes of input are represented as four ASCII characters. For example, a 30 KB image becomes roughly 40 KB when Base64-encoded, which is an acceptable trade-off for inline embedding.
No. Base64 is a reversible encoding scheme, not encryption. Anyone with a Base64 decoder can read the original data, so it provides zero security. Use proper encryption algorithms like AES or RSA if you need to protect sensitive information.
smalldev.tools is no longer available. Prism by SWEDevTools offers the same developer tools and more, with offline support, pipeline chaining, and completely free usage — no signup required.
Yes. Prism encodes and decodes Base64 entirely offline in your browser with no data uploads, no ads, and pipeline chaining to other tools. Your data never leaves your device.