Base64 Tools

Encode and decode Base64 directly in the editor. Select some text, run a command, and the selection is replaced in place with the result — no side panel, no scratch file. Decoding also recognises base64url and JWT-shaped strings, so pasting a token and expanding it into readable JSON is one keystroke.

Features

• Encode the selection. The selected text is read as UTF-8 and replaced with standard Base64 — the A–Z a–z 0–9 + / alphabet with = padding. The selection is encoded exactly as it stands, whitespace and newlines included; nothing is trimmed on the way in.

• Decode the selection, accepting more than one spelling. Leading and trailing whitespace is trimmed first, then the text is matched against standard Base64 (+, /, and zero to two trailing = — padding is optional) or against base64url (- and _, padding added back for you). The bytes are read back as UTF-8.

• JWT-shaped strings are expanded, not just decoded. If the selection splits on . into two or more base64url parts, each part is decoded separately; any part that parses as JSON is re-printed with two-space indentation. For a three-part token the last part — the signature, which is binary, not text — is left untouched.

• Right-click and keyboard access. Both commands appear in the editor context menu whenever there is a selection, and both have chord keybindings.

Both commands act on the primary selection of the active editor. If nothing is selected you get a Base64 Tools: No text selected. warning, and if the selection is not valid Base64 you get Base64 Tools: Selection is not valid base64. — in neither case is the document touched.

Encoding

Select Hello, World! and run Base64: Encode Selection to Base64. The selection becomes:

SGVsbG8sIFdvcmxkIQ==

Encoding always emits the standard alphabet with padding. There is no base64url encode command; decoding accepts base64url, encoding does not produce it.

Decoding

Running Base64: Decode Selection from Base64 reverses that. Padding may be missing, and surrounding whitespace is ignored, so all three of these decode to Hello:

SGVsbG8=
SGVsbG8
  SGVsbG8=

Whitespace inside the string is not stripped, so a wrapped or space-separated blob like SGVs bG8= is rejected rather than silently repaired.

base64url input works too — SGVsbG8-V29ybGQ_ decodes to Hello>World?.

JWT-shaped strings

Decoding checks for a dot-separated shape before it tries plain Base64. Select a token like:

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

and decoding replaces it with:

{
  "alg": "HS256",
  "typ": "JWT"
}
.
{
  "sub": "1234567890",
  "name": "John Doe",
  "iat": 1516239022
}
.
SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

The parts are rejoined with a . on its own line, so the structure of the original token is still legible. Two-part strings (a header and payload with no signature) are handled the same way, with both parts decoded. A part that does not contain JSON is left as its decoded text rather than being reformatted.

This is a decoder, not a validator: the signature is copied through verbatim and nothing is verified. Do not treat a decoded token as a trusted one.

Commands

Both are available from the Command Palette and from the editor context menu (shown only when text is selected).

Keybindings

Both are chords, and both are active only when the editor has focus and a selection.

Settings

This extension contributes no settings.