Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to text — instant, fully offline
Frequently Asked Questions
Base64 encoding converts binary or text data into a text-safe format using only 64 printable characters, which is why it shows up constantly in contexts like email attachments, embedded images in web pages, and API data payloads — anywhere binary data needs to travel safely through a system designed for plain text.
Why Base64 exists — and what it isn't
Base64 solves a specific problem: many older systems, protocols, and text fields were designed to handle only printable text characters, not arbitrary binary data, which could contain byte sequences that get corrupted or misinterpreted when passed through a text-only channel. Base64 re-encodes any input (including binary files) into a sequence using only 64 safe characters (A–Z, a–z, 0–9, plus two symbols), guaranteeing it survives transmission through text-oriented systems intact. It's important to be clear about what Base64 is not: it is not encryption, and provides no security or confidentiality — anyone can decode Base64 back to the original data instantly, since the encoding scheme is a fully public, standard, reversible transformation, not a secret. Base64-encoded data is also always larger than the original — roughly 33% larger — since encoding 3 bytes of original data into 4 Base64 characters is a fixed expansion ratio built into the scheme.
A worked example
A short piece of plain text and its Base64-encoded version look nothing alike at a glance, but decoding the Base64 string returns exactly the original text — the transformation is completely reversible and lossless, just visually opaque to a casual reader, which is precisely the "text-safe transport" property Base64 is designed to provide.
How this connects to your other technical calculations
For a different text transformation used in a different context — making text safe for inclusion in a URL rather than a general text channel — the URL Encoder/Decoder handles that related but distinct encoding scheme.
Common mistakes
Assuming Base64 encoding provides any privacy or security protection is the most consequential misunderstanding — Base64 is purely a format transformation, fully and trivially reversible by anyone, and should never be used as a substitute for actual encryption when data genuinely needs to stay confidential.