Is this Base64 tool Unicode-safe?

Yes. It uses TextEncoder and TextDecoder to handle Unicode correctly, so characters beyond ASCII including emoji work as expected.

How do I make URL-safe Base64?

Use the URL-safe variant where the plus sign is replaced with a hyphen and the slash is replaced with an underscore. Padding may be omitted depending on your use case.

Does any data leave my browser?

No. All encoding and decoding is performed locally in your browser and nothing is uploaded.

How to convert image to Base64?

Use the file upload tab – drag & drop any image and get Base64 instantly.

Is this Base64 tool private?

Yes – everything runs locally in your browser. No data is sent to any server.

Does it support URL-safe Base64?

Yes – toggle the URL-safe option to replace + with - and / with _ automatically.

RFC 4648 Compliant

Online Base64 Encoder & Decoder Tool

Encode text or files to Base64 and decode them back instantly. Supports UTF-8, URL-safe variant, line wrapping, and drag-and-drop file uploads. Everything stays in your browser.

Input — Plain text

file.bin

0 KB

Output — Base64

0 input bytes 0 output chars +0% size change 0 lines

Error Something went wrong.

Options

URL-safe (Base64URL) Strip padding (=) Wrap lines Output as Data URI

Live processing

Try an example

Text & Files

Encode any text, image, PDF, or binary up to 10 MB with drag-and-drop.

URL-Safe Variant

Switch to Base64URL for JWT, query strings, or filenames — no special characters.

Data URI Output

Generate data: URIs ready to drop into HTML or CSS.

100% Private

All conversion happens locally. Your text and files never leave your device.

What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme defined by RFC 4648. It represents binary data as a string of 64 printable ASCII characters, making it safe to transmit through systems that only handle text — like email, JSON, XML, or URL parameters.

Every 3 bytes of binary data become exactly 4 Base64 characters, which means encoded output is roughly 33% larger than the original. The trailing = characters (padding) ensure the output length is always a multiple of 4.

Standard vs URL-safe Alphabet

The standard Base64 alphabet uses + and /, which conflict with URL syntax. The URL-safe variant (also called Base64URL) replaces them with - and _ — it's used in JSON Web Tokens (JWT), URL parameters, and S3 object keys.

Standard (RFC 4648 §4)

            A–Z, a–z, 0–9, +,
            /   padding: =
          

URL-safe (RFC 4648 §5)

A–Z, a–z, 0–9, -, _ padding: optional

Common Use Cases

Embedding images directly in HTML/CSS via data: URIs, encoding email attachments (MIME), storing binary data in JSON or XML, transmitting files in API request bodies, JSON Web Tokens (JWT) where each part is Base64URL-encoded, basic HTTP authentication headers, and storing certificates and SSH keys in PEM format.

Important: Base64 is NOT encryption

Base64 is encoding, not encryption. Anyone can decode it without a key. Don't use it to "hide" passwords, secrets, or sensitive information — for that, use proper encryption like AES-256.

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