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Base64 Encoder/Decoder

Encode text or files to Base64, or decode Base64 back — right in your browser. Supports text and file mode.

Works offlineNothing uploaded

How to use it

1

Paste your text or Base64

Enter plain text to encode or a Base64 string to decode.

2

Choose encode or decode

Select whether to encode to Base64 or decode from Base64.

3

Copy the result

Click copy to grab your encoded or decoded output.

When to use Base64 Encoder/Decoder

A PR review has a gnarly base64 blob in an environment variable — could be a private key, could be a config JSON, could be garbage. Paste it here and decode it back to plain text in one click using JavaScript's native `atob` / `btoa` under the hood. Go the other way just as fast: paste a private key or a binary config and get the base64 string to drop into a Kubernetes secret or a CI environment variable. Supports text mode for strings and file mode for binary payloads like images embedded in CSS data URIs. Nothing you decode leaves this browser tab — no server receives the blob, which matters because a valid private key can be replayed immediately.

  • Decode a base64 env var from a PR to check for secrets
  • Encode a service account JSON for a Kubernetes secret
  • Inspect the payload of a base64 data URI from a CSS file

About this tool

Base64 shows up everywhere — email attachments, CSS data URIs, JWT payloads, API responses that embed images as strings. Paste any text or drop a file and get the encoded output instantly; paste a Base64 string and decode it back just as fast. Supports both text mode and file mode, so you can round-trip binary data without leaving the browser. No server sees your input — encoding and decoding run locally using JavaScript, which means sensitive payloads, private keys, and internal configs never touch an outside system. Copy the result with one click.

Frequently asked

Is this Base64 encoder private? Does it send my data to a server?
No. Encoding and decoding use JavaScript's built-in atob and btoa functions inside this tab — your text and file payloads never leave the browser, and the tool works without a network connection.
What is Base64 encoding?
Base64 converts binary data into ASCII text, commonly used for embedding images in CSS, email attachments, and API data transfer.
Can I encode files?
Yes — switch to File mode to encode any file to Base64 or decode a Base64 string to a file.
Is there a size limit?
It runs on your computer, so very large files may be slow. For text, there is no practical limit.

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