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Tools/Base64

Base64 encode / decode

base64encode.org is the old bookmark. This one does UTF-8 properly (btoa alone will throw on emoji), speaks base64url for JWTs, and can turn a small file into a data URI — all on-device.

Plain text (UTF-8)

Base64

21 bytes · hex 64 65 76 74 6f 6f 6c 73 2e 73 75 70 73 74 75 64 69 6f 2e 69 6e

JWT header/payload is base64url. Open the JWT decoder for three-segment tokens.

File → data URI

Stays in this tab. Keep files small.

In code

const bytes = new TextEncoder().encode(text);
btoa(String.fromCharCode(...bytes));
new TextDecoder().decode(Uint8Array.from(atob(b64), (c) => c.charCodeAt(0)));

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