What's the encoding overhead?

~33% larger than the original. 3 bytes become 4 chars. Worth it for safe embedding in JSON, XML, HTML, or URLs.

Standard or URL-safe?

Standard by default (includes +/=). Toggle for URL-safe (-_= no padding) when embedding in URLs or query strings.

Yes — upload a file to encode. Useful for embedding images as data URIs or encoding binary payloads for APIs.

Yes — newlines are included in the encoded output. Newlines in the encoded (base64) output are optional line breaks for readability.

Encode text or files to Base64. Part of the DevTools Surf developer suite. Browse more tools in the Encoding collection.

Base64 encoding increases data size by ~33%. It uses 64 characters (A-Z, a-z, 0-9, +, /) to represent binary data.
Base64 was first standardized in RFC 1421 (1993) for Privacy Enhanced Mail (PEM) — the same format used for SSL certificates today.
The '=' padding at the end of base64 strings exists because the input must be divisible by 3 bytes; padding fills the gap when it's not.

What's the encoding overhead?: ~33% larger than the original. 3 bytes become 4 chars. Worth it for safe embedding in JSON, XML, HTML, or URLs.
Standard or URL-safe?: Standard by default (includes +/=). Toggle for URL-safe (-_= no padding) when embedding in URLs or query strings.
Does it handle binary files?: Yes — upload a file to encode. Useful for embedding images as data URIs or encoding binary payloads for APIs.
Can I paste multiline text?: Yes — newlines are included in the encoded output. Newlines in the encoded (base64) output are optional line breaks for readability.

Encode text or files to Base64. Part of the DevTools Surf developer suite. Browse more tools in the Encoding collection.

Base64 encoding increases data size by ~33%. It uses 64 characters (A-Z, a-z, 0-9, +, /) to represent binary data.
Base64 was first standardized in RFC 1421 (1993) for Privacy Enhanced Mail (PEM) — the same format used for SSL certificates today.
The '=' padding at the end of base64 strings exists because the input must be divisible by 3 bytes; padding fills the gap when it's not.

What's the encoding overhead?: ~33% larger than the original. 3 bytes become 4 chars. Worth it for safe embedding in JSON, XML, HTML, or URLs.
Standard or URL-safe?: Standard by default (includes +/=). Toggle for URL-safe (-_= no padding) when embedding in URLs or query strings.
Does it handle binary files?: Yes — upload a file to encode. Useful for embedding images as data URIs or encoding binary payloads for APIs.
Can I paste multiline text?: Yes — newlines are included in the encoded output. Newlines in the encoded (base64) output are optional line breaks for readability.