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Base64 Encoder / Decoder

Encode and decode Base64 online — free.

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This free Base64 encoder and decoder converts text to Base64 and back, instantly. Base64 represents binary or text data using 64 safe ASCII characters, so it can travel through systems that only handle text — like data URIs, JSON, JWTs and email.

How to use it

  1. Paste your text or Base64 string.
  2. Choose Encode or Decode.
  3. Copy the converted result.

Frequently asked questions

What is Base64?

Base64 is an encoding that represents data using 64 printable ASCII characters (A–Z, a–z, 0–9, + and /), so binary content can be stored or sent as plain text.

Is Base64 a form of encryption?

No. Base64 is encoding, not encryption — anyone can decode it. Never use it to protect sensitive data; use real encryption for that.

When is Base64 used?

To embed images in HTML/CSS as data URIs, encode attachments in email, carry binary data in JSON or JWTs, and pass data safely through text-only channels.

What does Base64 Encoder / Decoder do?

Encode and decode Base64 online — free.

When would I actually use this?

Reading a payload someone sent you, embedding a small file in a config, and finding out why a query string breaks once it reaches the server.

What is the most common mistake?

Treating Base64 as a form of protection. It is an encoding, not encryption — anyone can decode it instantly, and a token pasted into a public issue is a leaked token.

How is Base64 Encoder / Decoder different from HTML Entity Encoder / Decoder?

They sit next to each other but answer different questions: HTML Entity Encoder / Decoder is the one to open when you need it to convert text to HTML entities and back, escaping <, >, &, quotes and optionally all non-ASCII characters. Pick whichever matches what you're starting from — both are free.

Is there a tool for the next step?

URL encoder / decoder is the closest one after this: Encode and decode URLs and query parameters.

What else is worth having open alongside it?

JWT decoder and UUID Validator / Decoder — they come up in the same task often enough to be worth a second tab.

Where do the figures come from?

The encodings follow their RFCs, so a round trip is lossless. URL encoding has two variants — one that encodes a space as %20 and one as a plus sign — and the tool says which it applies.

Further reading

All guides →
ExplainerWhat Is Base64 Encoding?Base64 turns binary data into safe text. Here's what it does, why it exists, why it isn't encryption, and the size cost it adds.GuideURL Encoding Explained: Percent-Encoding and Where It BitesPercent-encoding is decided per URL component, which is the whole source of the confusion. A slash is legal in a path and must be escaped in a query value; a space is %20 in a path and may be + in a form body. Here are the exact RFC 3986 sets, the three JavaScript functions that disagree, and the traps.ExplainerWhat Is a JWT (JSON Web Token)?A JWT is a compact, signed token used to carry identity between services. Here's its three parts, how it's used for auth, and its security limits.GuideBuilding a URL With Parameters That Survives a Copy-PasteThree encodings, one visible difference: %20 or +. The builder's form mode matches URLSearchParams byte for byte on seventeen values — but give it a base URL with a fragment and every parameter lands inside the hash, where no server sees it.ExplainerWhat Is Inside a JWT — and What It Does Not ProtectA JWT is signed, not encrypted. Anyone holding the token can decode the payload and read every claim in it. Here is a real token, decoded without any key, plus the three attacks the signature is supposed to stop and the one problem it cannot solve.ComparisonJSON vs XML: What's the Difference?JSON and XML both store structured data as text, but they trade off differently. Here's how each looks, where each wins, and how to choose.