64
Free Base64 Encoder & Decoder
Use this free Base64 encoder and decoder to instantly convert text to Base64 or decode any Base64 string back to plain text. Paste your input, select encode or decode, and get your result in one click. Everything runs in your browser — nothing is sent to any server. Whether you need to encode API credentials,decode a JWT payload, convert an image to a Base64 data URI, or just understand what a Base64 string contains, this free online Base64 converter handles it all with no sign up required
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Output
Output will appear here...
Base64 Encoding Use Cases & Format Reference
| Use Case | Where You See It | Variant | Example Format |
|---|---|---|---|
| JWT Tokens | OAuth 2.0, API authentication headers | Base64URL | eyJhbGciOiJIUzI1NiJ9... |
| Image Data URIs | HTML src, CSS background-image | Standard | data:image/png;base64,iVBOR... |
| HTTP Basic Auth | Authorization request header | Standard | Basic dXNlcjpwYXNzd29yZA== |
| Email Attachments | MIME encoded email bodies | MIME (76-char lines) | Content-Transfer-Encoding: base64 |
| JSON Binary Data | API responses with binary payloads | Standard | {"image": "SGVsbG8gV29ybGQ="} |
| PEM Certificates | SSL/TLS certificate files | Standard | -----BEGIN CERTIFICATE----- |
| URL Parameters | Query strings, routing tokens | Base64URL | token=SGVsbG8-V29ybGQ_ |
* Base64 increases data size by approximately 33% — 3 bytes of input always produce 4 characters of output.
Frequently Asked Questions
What is Base64 encoding?+
Base64 is a way to represent binary data as plain ASCII text. Commonly used to embed images in HTML or CSS, encode API credentials, and transmit data over text-based protocols.
Is Base64 the same as encryption?+
No. Base64 is encoding, not encryption. Anyone can decode a Base64 string — it provides no security. Do not use it to hide sensitive data.
What does a Base64 string look like?+
Base64 strings use letters, numbers, plus (+), and slash (/), often ending with one or two equals signs (=) as padding. Example: SGVsbG8gV29ybGQ=
Why does my Base64 string end with == ?+
The equals signs are padding characters added when the input length is not divisible by 3. They are a normal and expected part of Base64 output.
Can I encode images to Base64?+
Yes. Base64-encoded images can be embedded directly in HTML or CSS using data URIs, removing the need for a separate image file request.