Base64 Decoder & Encoder
Decode Base64 to text or files, or encode any string or file to Base64 — instantly, privately, in your browser.
Need a focused tool? Try the dedicated Base64 Decode or Base64 Encode pages.
Private by design
Everything runs in your browser. Nothing is uploaded, logged, or stored on a server.
Instant conversion
Real-time encoding as you type, with optional auto-detect for plain text or Base64 input.
Files and text
Encode any file to a Base64 string, or decode strings back into downloadable files.
How Base64 decoding & encoding works
Base64 encoding takes binary data — text, an image, a PDF, a certificate — and represents it using only 64 ASCII characters (A–Z, a–z, 0–9, +, /) so it can travel safely through systems that only understand text: email (MIME), JSON payloads, HTTP headers, HTML/CSS data:URLs, and YAML config. Base64 decoding reverses the process and reconstructs the original bytes.
Base64 is not encryption — it's reversible and adds no security. Anyone with a Base64 string can decode it back to the original bytes.
Frequently asked questions
›How do I decode a Base64 encoded string?
Paste your Base64 string into the input box above and choose the Decode mode (or leave it on Auto). The decoded text appears instantly in the output. For files, switch to the File tab, paste a Base64 string, and download the resulting binary file. Everything is processed in your browser — nothing is uploaded.
›What is Base64 encoding?
Base64 is a binary-to-text encoding scheme that represents arbitrary binary data using a 64-character alphabet (A–Z, a–z, 0–9, + and /). It's commonly used to safely transmit binary content over channels that only support text, such as email, JSON payloads, and data URLs in HTML or CSS.
›How do I Base64 encode text online?
Type or paste your text into the input box, select Encode mode, and the Base64 output updates as you type. You can change the source character set (UTF-8, ASCII, UTF-16, ISO-8859-1, Windows-1252) using the charset dropdown. Click the copy button to grab the result.
›Is my data sent to a server?
No. Every encode and decode operation runs locally in your browser using built-in JavaScript APIs. Your text and files never leave your device, which makes the tool safe to use for sensitive content.
›Can I encode and decode files?
Yes. Switch to the File tab to upload any file (images, PDFs, archives, certificates, etc.) and convert it to a Base64 string, or paste a Base64 string and download the resulting file.
›Does it support Unicode characters and emoji?
Yes. Text is encoded as UTF-8 bytes before Base64 conversion, so multilingual text and emoji round-trip correctly. You can also switch to other character sets like ISO-8859-1, Windows-1252, UTF-16 LE/BE, or ASCII.
›Is this tool free?
Yes, it's completely free with no signup. We may introduce non-intrusive advertising in the future to support hosting and ongoing development.
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