Base64 encoder decoder online.
Decode what's hiding in that encoded string. Convert between Base64 and plain text instantly.
Paste text or drop a file
Type plain text to encode, or drag a file onto the input panel for raw Base64 output.
Converts text to Base64 format and back · ⌘↵ toggles encode/decode
How to use the Base64 encoder decoder online
- Paste plain text, binary output, or data URLs into the editor, or drag a file when you need base64 encode image online free workflows for frontend embedding.
- Choose encode mode to convert source content into Base64, or decode mode to inspect existing values such as auth headers, JWT segments, and serialized payloads.
- Enable URL-safe mode when integration targets require `-` and `_` instead of `+` and `/`, such as tokens and query-parameter transport formats.
- Copy the final output into your application, API tooling, or documentation after validating content type detection and byte-size impact.
What is Base64 Encoding?
Base64 is a binary-to-text encoding standard that converts arbitrary bytes into printable ASCII characters for systems that primarily handle text. A Base64 encoder decoder online is useful when you need to move binary data through JSON payloads, HTTP headers, email bodies, or configuration files that do not tolerate raw bytes. Developers frequently use Base64 for inline assets, API authorization headers, token transport, and debugging encoded strings from third-party services. Because encoding expands payload size by roughly one third, it is best used for compatibility and convenience rather than compression. This tool supports standard and URL-safe variants, text and file workflows, and fast decode checks to identify underlying content. Everything runs in your browser, so sensitive strings and files stay local while you convert, inspect, and reuse encoded output securely.
Frequently asked questions
Is Base64 encryption?+
No. Base64 is only an encoding layer, so anyone can decode Base64 string data without a key. Use it for transport compatibility, not confidentiality. For secure storage or transmission, combine encoding with encryption and proper key management.
Why is Base64 output longer than input?+
Base64 maps 3 bytes of binary data into 4 text characters, which increases size by about 33 percent. That overhead is expected and is the tradeoff for text-safe transfer across systems that reject raw binary payloads.
What is URL-safe Base64?+
URL-safe Base64 replaces `+` and `/` with `-` and `_` so encoded values can be used in URLs, tokens, and query parameters without escaping issues. Some implementations also trim padding characters for compact transport.
Can I base64 encode image online free?+
Yes. Upload or drag an image file and the tool will output Base64 text you can embed directly in HTML, CSS, or JSON payloads. This is useful for prototypes, email templates, and small inline assets.
What can this decoder auto-detect?+
When decoding, the tool identifies likely content classes such as JWT, JSON, image data, XML, or plain text. That quick classification helps you understand unknown payloads before using them in downstream systems.