What is URL-safe Base64?

Standard Base64 uses `+` and `/` characters that have special meanings in URLs (`+` means space; `/` separates path segments). URL-safe Base64 replaces `+` with `-` and `/` with `_`, making the encoded string safe for use in URLs, query parameters, and filenames without percent-encoding. JWT tokens and OAuth codes use URL-safe Base64.

Is Base64 encryption?

No. Base64 is encoding, not encryption. The transformation is entirely reversible without any key — anyone with a Base64 decoder (including this tool) can immediately read the original data. Do not use Base64 to obscure sensitive information like passwords or tokens. Use AES-256 or another cryptographic algorithm for actual data security.

Where is Base64 used?

Base64 appears throughout software: JWT tokens (header and payload are Base64-encoded), data URIs for embedding images directly in CSS/HTML (`src="data:image/png;base64,..."`), HTTP Basic Authentication headers, MIME email attachments, X.509 certificates in PEM format, and storing binary blobs in JSON or XML payloads that must contain only printable characters.

Can I encode files to Base64?

Yes. Select a file and the tool reads it using the browser's FileReader API, then encodes the binary content to a Base64 string — no upload to any server occurs. This is useful for embedding small images or fonts directly in CSS/HTML as data URIs, or for copying file content into API payloads that expect Base64-encoded binary data.

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Free Base64 Encoder & Decoder — Online, No Login

Base64 encoding converts binary data or text into a printable ASCII string using 64 characters (A–Z, a–z, 0–9, +, /). It is used to transmit binary data over channels that only support text — email attachments, data URIs, JWT tokens, and API payloads. This tool encodes and decodes instantly in the browser.

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How It Works

How to use Base64 Encoder / Decoder

Choose Encode or Decode

Select whether you want to convert text to Base64 or decode a Base64 string back to plain text.

Paste your input

Enter the text or Base64 string. Optionally enable URL-safe mode (replaces + with - and / with _).

Copy the result

The output updates instantly. Click Copy to clipboard.

FAQ

Frequently asked questions

Base64 encoding converts binary or text data into a string of 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It increases data size by approximately 33% but ensures the data can safely pass through text-only channels like email systems, JSON fields, and HTTP headers that cannot reliably transmit arbitrary binary data.

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References

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Free Base64 Encoder & Decoder — Online, No Login

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