Base64 Encoder & Decoder
Encode plain text to Base64 or decode Base64 strings back to readable UTF-8 text instantly in your browser.
How Base64 encoding works
Base64 is a standard encoding scheme that represents 8-bit binary data using a radix-64 representation. It takes every 3 bytes (24 bits) of data and splits them into 4 6-bit groups. Each 6-bit index (ranging from 0 to 63) maps directly to one of 64 printable ASCII characters: A–Z, a–z, 0–9, +, and /.
When to use Base64
- Web API Payloads: Embedding raw binary data or authorization header tokens (
Basic YWRtaW46cGFzc3dvcmQ=) in HTTP REST and GraphQL headers. - Inline HTML & CSS: Embedding small raster icons, SVG data URIs, or fonts directly into CSS stylesheets to eliminate HTTP request overhead.
- Data Transport: Passing structured parameters safely inside JSON fields or email MIME attachments without syntax escaping conflicts.
Frequently Asked Questions
Is Base64 an encryption algorithm?+
No. Base64 is a binary-to-text encoding format designed to transport binary data safely over text-only protocols like HTTP, email, and JSON. It provides no confidentiality, secrecy, or cryptographic security.
Does Base64 encoding increase string or file size?+
Yes. Base64 encoding increases data size by roughly 33% because every 3 bytes of binary data are converted into 4 printable ASCII characters (plus padding '=' characters if needed).
Does this tool support UTF-8 special characters and emojis?+
Yes. ShadTools uses full UTF-8 byte encoding before converting to Base64, so accented characters, non-Latin alphabets, and emojis encode and decode perfectly without corruption.
Is my data sent to any remote server or stored online?+
Never. All transformations execute 100% client-side inside your browser tab memory. Your text never leaves your local device.