How it works
Type text or pick a small file; the encoder converts bytes to a Base64 string locally for copy or download.
Encode text or files to Base64 without uploading anywhere.
Plain text
Base64 output
Type text or pick a small file; the encoder converts bytes to a Base64 string locally for copy or download.
Conversions run in your tab with JavaScript — no desktop app required.
Files stay on your device during processing. We do not receive your uploads.
Heavy codecs and AI models run locally via Web Workers and WASM (FFmpeg.wasm, Transformers.js).
Type text or pick a small file; the encoder converts bytes to a Base64 string locally for copy or download.
Large files may exceed memory limits. This tool encodes bytes; it does not encrypt content. Processing is 100% offline in your browser — files never leave your device.
Yes. This tool is free convert online with no signup. Processing stays in your browser — no uploads.
You control quality settings. Choose higher quality for no quality loss when converting online.
Every conversion runs inside your browser tab using JavaScript and Web Workers. There is no background server queue and no account is required for core tools.
Your files are never uploaded to FreeConvertKit for processing. Originals, previews, and exports stay on your device unless you choose to download or share them yourself.
When codecs or AI models are needed, WebAssembly modules such as FFmpeg.wasm and Transformers.js execute locally — giving you desktop-class power with absolute file privacy.
Inspect JSON Web Token headers and payloads locally.
Convert HEX, RGB, and HSL with a live preview.
Beautify, minify, and validate JSON with syntax highlighting in the browser.
Generate SHA-256 and other hashes from text in the browser.