Policy Document Base64 Encoder/Decoder

Some AWS workflows and adjacent tooling expect a policy document (or any text) as a Base64 string rather than raw text — embedding it inside another payload, passing it through a system that only accepts opaque blobs, or matching a particular API's expected input encoding. Policy Document Base64 Encoder/Decoder converts pasted text to Base64 and back, using the browser's native btoa/atob functions so the conversion matches exactly what a browser-based script doing the same thing would produce.

Encoding accepts any text, not just policy JSON — paste a policy document, a fragment, or anything else you need encoded. Decoding validates the input before attempting to decode it: text containing characters outside the standard Base64 alphabet, or text with an invalid length/padding, is rejected with a specific error message rather than letting a raw browser exception through.

One honest caveat: btoa/atob only handle Latin1/ASCII text correctly. IAM policy JSON is virtually always plain ASCII, so this rarely matters in practice, but if your text contains non-Latin1 Unicode characters, native btoa can throw or misbehave — a limitation of the browser API this tool intentionally keeps simple rather than working around.

• Encode any text (including policy JSON) to Base64.
• Decode Base64 back to text, with input validation.
• Clear error messages on invalid Base64 input instead of a raw exception.
• One-click copy of either result.
• Sample policy JSON to try encoding instantly.
• 100% client-side — nothing is uploaded.

1. To encode: paste text (or click the sample) in the Encode box and click Encode.
2. To decode: paste Base64 text in the Decode box and click Decode.
3. Copy the result with the copy button next to each output.

Example 1 — encode. {"Version":"2012-10-17","Statement":[]} encodes to eyJWZXJzaW9uIjoiMjAxMi0xMC0xNyIsIlN0YXRlbWVudCI6W119.

Example 2 — decode. Pasting that same Base64 string into the decoder returns the original JSON exactly.

Example 3 — invalid input. Pasting plain text with spaces and punctuation into the decoder (not valid Base64) returns a clear "does not look like valid Base64" error instead of garbage output.

• Encode or decode in one place, no separate CLI or online tool needed.
• Validates before decoding, so bad input fails clearly instead of silently.
• Uses the browser's native, standards-based Base64 implementation.
• Private — encoding/decoding runs entirely in your browser.