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Base64 Encoder / Decoder

Encode text to Base64 or decode Base64 to text. Use "text|||decode" to decode.

Paste text to encode it into Base64, or paste a Base64 string to decode it back to its original form — the tool switches direction with a single toggle and updates instantly. Base64 is an encoding, not encryption: it makes data safe to transport through text-only systems but provides no security, since anyone can decode it. It's the standard way to embed images in CSS, carry binary data in JSON, or pack values into data URIs.

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Quick answer

Paste text to encode it into Base64, or paste a Base64 string to decode it back to its original form — the tool switches direction with a single toggle and updates instantly. Base64 is an encoding, not encryption: it makes data safe to transport through text-only systems but provides no security, since anyone can decode it. It's the standard way to embed images in CSS, carry binary data in JSON, or pack values into data URIs.

What is Base64 Encoder / Decoder?

The Base64 Tool is a free online encoder and decoder that converts text to Base64 and back again directly in your browser. Base64 represents binary or text data using only 64 safe ASCII characters, which lets you embed or transmit content through channels that expect plain text. Because everything runs client-side, the data you convert is never sent anywhere.

How to use Base64 Encoder / Decoder

  1. 1

    Choose a direction

    Decide whether you want to encode plain text into Base64 or decode an existing Base64 string back to its original form, and set the tool to that mode.

  2. 2

    Paste your input

    Drop your text or Base64 string into the input field. For decoding, make sure you paste the complete string including any trailing = padding characters, which are part of the encoding.

  3. 3

    Read the result

    The converted output appears immediately. Encoded Base64 uses only letters, digits, +, /, and = padding; if a decode produces garbled characters, the input probably wasn't valid Base64 or used a URL-safe variant.

  4. 4

    Copy and use it

    Copy the output into your data URI, JSON field, config file, or wherever you need it. When embedding in a URL, remember to use Base64URL or URL-encode the +, /, and = characters.

Try it when you need to…

  • You need to inline a small logo into CSS without an extra HTTP request and want its data URI
  • An API returned a Base64 blob and you need to read what's actually inside it
  • You must pass binary or multiline data through a text-only field that would otherwise mangle it

Use cases

  • Encode a small image or font into a data URI so it can be embedded directly in HTML or CSS
  • Decode a Base64 payload from a JSON API response to inspect the underlying content
  • Encode binary data so it survives transport through email or a text-only field
  • Decode the segments of tokens and credentials that are stored in Base64 form
  • Prepare Base64-encoded values for configuration files and environment variables

Key features

Two-way conversion — encode text to Base64 and decode Base64 back to text
Instant output that updates as you type or paste
Handles multiline input and preserves the original formatting on decode
One-click copy of the encoded or decoded result
Fully client-side, so nothing you paste is uploaded or stored

Tips & best practices

Base64 is encoding, not encryption. It offers zero confidentiality because anyone can decode it instantly — never use it to hide secrets or protect sensitive data.

Base64 inflates size by about 33%, since every 3 bytes become 4 characters. Keep that overhead in mind before inlining large images, which can bloat your HTML and hurt load times.

Standard Base64 uses + and /, which have special meaning in URLs. For query strings and JWTs use the URL-safe variant that substitutes - and _ instead.

The trailing = signs are padding, not decoration. They pad the output to a multiple of four characters, and stripping them can cause a strict decoder to reject the string.

Frequently asked questions

No. Base64 is a reversible encoding that anyone can decode without a key or password, so it provides no security whatsoever. It exists to represent binary data as text for safe transport, not to keep data secret — for confidentiality you need actual encryption.

Base64 encodes every 3 bytes of input into 4 output characters, which adds roughly 33% to the size. This overhead is the trade-off for making the data text-safe, and it's why inlining large files as Base64 can noticeably increase page weight.

They are padding characters that round the encoded length up to a multiple of four. One or two = signs appear when the input length isn't divisible by three. They're a required part of standard Base64, and some strict decoders will reject a string that's missing them.

Standard Base64 uses + and / as its last two characters, but those have reserved meanings in URLs. URL-safe Base64 replaces them with - and _ and often drops the = padding so the string can be placed directly in a URL or used in a JWT without additional encoding.

That usually means the input wasn't valid Base64, was a URL-safe variant, or actually encoded binary data like an image rather than text. Base64 doesn't record what type of data it holds, so decoding raw bytes as text yields gibberish even when the decode itself succeeded.

This tool focuses on text, and Base64-encoding text is exactly what you need to build data URIs by hand or inspect payloads. For a full image you'd typically read the raw bytes first; the resulting Base64 string can then be prefixed with a data URI header like data:image/png;base64, for embedding.

No. Both encoding and decoding happen in your browser using built-in functions, so whatever you paste stays on your device. That makes it safe to decode payloads that may contain sensitive information.

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