Convert an Uint8Array to a base64 encoded string

Encode byte values as base64 with btoa.

JavaScript Version 1.0.0 · MIT · .md

function bytesToBase64(bytes) { return btoa(String.fromCharCode(...bytes)); }

Input & expected output

[
  72,
  101,
  108,
  108,
  111
]

"SGVsbG8="

The edge case

[]

""

Know the limits

• Spreading is fine for the lab’s 1,000 bytes. For files, use Buffer.from(bytes).toString("base64") in Node.js or encode in chunks.
• This is the encoding Oveyon expects in an attachment’s content field.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Keep exploring

• Capitalize a string — Uppercase the first Unicode code point and preserve the remaining text.
• Reverse a string — Reverse Unicode code points without splitting surrogate pairs.
• Check a palindrome — Compare a string with its code-point reversal.