Base64 to JSON Converter

Base64 → JSON JSON → Base64

Paste Base64 or Base64URL

Indentation

Runs entirely in your browser. A data: URL prefix and line breaks in the input are ignored.

What does this tool do?

Many APIs, tokens and config values carry JSON inside a Base64 string. This tool decodes the Base64 (standard or URL-safe), checks that the result is valid JSON, and shows it nicely indented. It can also work backwards: paste JSON and get Base64 or Base64URL.

How to use it

Choose Base64 → JSON or JSON → Base64.
Paste your input. A leading data: prefix and line breaks are removed automatically.
Pick an indentation and press Convert, then copy the output.

Example

Decoding this Base64 string:

eyJuYW1lIjoiQXNoYSIsImFnZSI6MzAsInNraWxscyI6WyJqcyIsInB5dGhvbiJdfQ==

gives:

{
  "name": "Asha",
  "age": 30,
  "skills": [
    "js",
    "python"
  ]
}

Frequently asked questions

What is the difference between Base64 and Base64URL?

Base64URL replaces + with - and / with _ and usually drops the = padding, so it is safe in URLs and filenames. This tool reads both.

Why do I get "not valid UTF-8"?

The data decodes to bytes that are not text, such as an image or a compressed file. Only text that is valid UTF-8 can be shown as JSON.

Why does it decode but say the JSON is invalid?

The text is not strict JSON. Common causes are single quotes, trailing commas, comments or unquoted keys. The raw decoded text is still shown so you can fix it.

Is Base64 encryption?

No. It only changes how data is written and anyone can reverse it, so do not use it to hide secrets.

Is my data uploaded?

No. Everything runs in your browser.

Results are estimates for information only and are not financial, tax or legal advice.