Developer Tools
~/base64-encoder
// Encode or decode Base64 instantly. Supports standard and URL-safe Base64.
Encode
Converts plain text or binary data into a Base64 ASCII string safe for transport in JSON, HTML, or URLs.
Decode
Converts a Base64 string back to its original plain text or binary representation.
URL-safe
Replaces + with - and / with _ so the output is safe to use directly in URLs without percent-encoding.
// FAQ
What is Base64 encoding?
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. Commonly used in email, data URIs, and API payloads.
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.
When should I use URL-safe Base64?
Use URL-safe mode when the Base64 output will be included in a URL or filename. It replaces + with - and / with _ to avoid encoding conflicts.
Why does my decoded output look like gibberish?
If the original data was binary (like an image or PDF), the decoded output will not be readable as plain text. Base64 decoding only produces readable text when the original input was text-based.
What is the size overhead of Base64?
Base64-encoded data is roughly 33% larger than the original. Every 3 bytes of input becomes 4 characters of Base64 output.
Is my data sent to a server when I encode or decode?
No. Everything runs locally in your browser. Your text never leaves your device.
// Common Use Cases
Embedding images in HTML or CSS
Convert small images to Base64 data URIs so you can inline them directly in your HTML or CSS without an extra HTTP request.
Authorization headers
Basic Auth encodes credentials as Base64. Use this tool to quickly generate or inspect Authorization header values during API development.
JWT inspection
JWT tokens use Base64url encoding for their header and payload. Decode the middle segment to inspect the claims without a dedicated tool.
Storing binary data in JSON
JSON cannot hold raw binary. Base64-encoding binary data (like file content or images) lets you include it safely in a JSON payload.