Base64 Encoder / Decoder

Encode and decode Base64 strings and files

Base64 is a group of binary-to-text encoding schemes that represent binary data in an ASCII string format. It is commonly used when there is a need to encode binary data that needs to be stored and transferred over media that are designed to deal with textual data.

How to use Base64 Encoder / Decoder

  1. Select Mode. Choose Encode to turn text to base64, or Decode to convert it back.
  2. Paste Input. Input your raw string or drag-and-drop a file.
  3. Copy Output. Instantly copy the result.

Features

  • Bidirectional Operations: Smoothly toggle between encoding raw strings and decoding base64 hashes.
  • URL-Safe Toggles: Swap standard characters to URL-safe hyphen/underscore characters and trim layout paddings.
  • Local Storage Processing: Completely offline execution ensures full compliance with privacy.

Why use this tool

  • Browser Native: Fast operations processed directly by browser APIs.
  • File Upload Encoder: Encode icons or small attachments directly into base64 text for embedding in HTML/CSS.

Frequently asked questions

Is Base64 encryption?

No. Base64 is an encoding, not encryption. It converts bytes into 64 printable characters so binary data can travel through text-only systems, and anyone can decode it instantly without a key. Never use Base64 to hide passwords, tokens or other secrets.

How do I decode a Base64 string?

Choose Decode, paste the Base64 text and the original text appears. For example, aGVsbG8= decodes to hello. If the input is not valid Base64 the tool shows an error instead, so check for missing characters, stray spaces or truncated padding.

How do I encode text or a file to Base64?

In Encode mode type or paste text and the Base64 output updates live. For example, Hello, World! becomes SGVsbG8sIFdvcmxkIQ==. You can also drop a file onto the tool to get its Base64 form. Text is encoded as UTF-8, so accented letters and emoji work.

Why does Base64 output end with = or == ?

The equals signs are padding. Base64 encodes 3 bytes as 4 characters, so when the input length is not a multiple of 3 the output is padded with one or two = characters to reach a multiple of 4. Padding carries no data and some systems omit it.

Why is Base64 output larger than the original?

Base64 output is about one third larger than the input, because every 3 bytes become 4 characters (a 33 percent increase). For example, 300 bytes of data become 400 characters. This overhead is the price of making binary data safe to put in text formats such as JSON, email or HTML.

Can I decode a Base64 image?

Yes. Paste a data:image URI, or a long raw Base64 string that looks like an image, in Decode mode and the tool shows a preview and a download link. Raw strings without a data: prefix are previewed as PNG, so other formats may not display correctly this way.

Is Base64 a form of encryption?

No. Base64 is an encoding format used to transmit data, not to secure it. It can be easily decoded by anyone and offers zero cryptographic security.

What is Base64?

Base64 is a binary-to-text encoding scheme that translates binary data into a set of 64 ASCII characters.

Are files sent to external servers?

No. File processing and encoding occur strictly within your local browser cache.

Is my data shared when using the Base64 Encoder / Decoder?

No. Toolskyt operates under a zero-server policy. All calculations, data formatting, and file exports are executed locally on your machine.

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