Base64 Decoder
Decode Base64 to text and files instantly
Input
Output
What is Base64 Decoding?
Need to decode Base64 data back to its original form? This tool converts Base64-encoded text and files back to readable content instantly. Base64 (RFC 4648) is commonly used in APIs, emails, and data transmission — this decoder reverses that encoding.
According to MDN Web Docs, Base64 decoding is essential when working with API responses, embedded images, or configuration files. Our decoder handles both standard and URL-safe Base64 formats.
Everything happens in your browser using native JavaScript atob() — your data stays private and secure.
What Makes This Tool Different
Text & File Decoding
Decode Base64 text directly or upload Base64-encoded files. Works with any valid Base64 string or file.
URL-Safe Support
Handles URL-safe Base64 (- and _ instead of + and /). Automatically detects and converts standard formats.
Real-Time Decoding
See decoded output instantly as you paste. No buttons to click — just paste Base64 and get results immediately.
Error Handling
Smart error detection for invalid Base64 strings. Clear messages help you fix padding or character issues.
Copy & Download
One-click copy to clipboard or download decoded content as a file. Perfect for saving API responses or embedded data.
Privacy First
All decoding happens locally in your browser. Sensitive Base64 data never leaves your computer or touches our servers.
How It Works
Paste Base64 Input
Paste your Base64 string into the left editor, or click "Upload" if you have a Base64-encoded file. Toggle "URL Safe" if your Base64 uses - and _ characters.
Automatic Decoding
The decoder processes your Base64 instantly and displays the original content on the right. Errors are caught and explained clearly.
Copy or Download
Click "Copy" to copy the decoded content to your clipboard, or "Download" to save it as a file. Use it immediately in your project.
When You'd Actually Use This
API Response Debugging
APIs often return Base64-encoded data. Paste the response here to decode and inspect the actual content — JSON, images, or binary data.
Email Attachments
MIME emails encode attachments as Base64. Decode email content to extract original files, images, or documents from raw email sources.
Data URI Extraction
Extract images from data URIs in HTML/CSS. Decode base64-encoded images embedded in stylesheets or inline code.
Configuration Files
Decode Base64 secrets, certificates, or keys from YAML, TOML, or JSON configs. Kubernetes secrets and CI/CD variables often use Base64.
Common Questions
Is my Base64 data stored?
No. All decoding happens in your browser using JavaScript atob(). Your Base64 data and decoded content never leave your computer.
Why am I getting "Invalid Base64" error?
Common issues: missing padding (=), invalid characters, or using URL-safe Base64 without enabling the checkbox. Check your input for spaces or newlines which should be removed.
What is URL-safe Base64?
URL-safe Base64 replaces + with - and / with _ to avoid URL encoding issues. Enable the checkbox if your Base64 comes from URLs or filenames.
Can I encode text too?
Yes! Use our Base64 Encoder to convert text or files to Base64 format. Perfect for preparing data for APIs or embedding.
Why does my decoded text look garbled?
The Base64 likely contains binary data (like an image or file) rather than text. Try the "File" mode to download the decoded content as a binary file instead.
Is there a size limit?
Large Base64 strings (10MB+) may cause browser performance issues. For very large files, consider using command-line tools or specialized software.
Other Base64 Tools You Might Need
Decoding is just one part of Base64 workflow: