Base64 Encoder & Decoder Online — Free Tool
This free Base64 encoder and decoder converts plain text or ASCII data to Base64 format and back — instantly in your browser, with no account or software needed.
What is Base64?
Base64 is a binary-to-text encoding scheme that represents binary data using a set of 64 printable ASCII characters (A–Z, a–z, 0–9, + and /). Each group of three bytes of input is encoded into four Base64 characters, making the output roughly 33% larger than the original. The name comes directly from the 64-character alphabet used.
Base64 was originally defined in RFC 2045 as part of the MIME standard for email attachments, and is now widely used across web protocols, APIs, and data serialisation formats.
What is Base64 used for?
Base64 encoding is useful whenever binary or non-printable data must travel through a text-only channel. Common real-world uses include:
- Email attachments — MIME encodes files as Base64 so binary content survives text-based mail transport.
- Data URIs — Images and fonts can be embedded directly in HTML or CSS as data:image/png;base64,… strings, eliminating extra HTTP requests.
- API payloads — JSON and XML cannot carry raw binary; Base64 lets developers transmit file contents or cryptographic keys safely inside these formats.
- Authentication tokens — HTTP Basic Authentication and JSON Web Tokens (JWT) use Base64 (or the URL-safe variant Base64url) to encode credentials and claims.
- Configuration files — Secrets and certificates are often Base64-encoded in environment variables or Kubernetes secrets to avoid quoting issues.
Base64 vs. encryption
Base64 is an encoding scheme, not encryption. Anyone with the encoded string can decode it instantly — no key is required. Do not use Base64 to protect sensitive data. For security, use proper encryption (AES, RSA, etc.) or hashing with a modern algorithm. Base64 is purely a way to represent data in a safe, text-friendly format.
Frequently asked questions
Is this Base64 tool free to use?
Yes, completely free. There is no signup, no subscription, and no usage limit. Paste your text, click the button, and get your result immediately.
How is Base64 different from encryption?
Base64 is encoding, not encryption. It converts data into a text-safe representation but provides no secrecy — anyone can decode it without a key. Use dedicated encryption algorithms if you need to protect sensitive information.
Can I decode any Base64 string back to its original text?
Yes, provided the original data was plain text (ASCII or UTF-8). If the Base64 string was produced from binary data such as an image or compressed file, decoding will return the raw binary bytes, which may not display as readable text.
Are my texts or data stored on the server?
No. The text you submit is processed to produce the encoded or decoded result and then deleted automatically. Nothing is retained after your session.
What characters does Base64 use?
Standard Base64 uses the 64-character set A–Z, a–z, 0–9, plus (+) and slash (/), with equals signs (=) used as padding. A URL-safe variant replaces + and / with hyphen (-) and underscore (_) to avoid issues in URLs and filenames.