Free Online Base64 Encoder & Decoder
Convert text and files to Base64, decode Base64 strings instantly — 100% private client-side processing
Base64 Processor
Upload File to Convert
Drag & drop a file here or click to browse
Supports: Any file type up to 10MB (Images, PDFs, Documents, etc.)
Multi-Encoding
UTF-8, ASCII, Latin-1, UTF-16 support
File Processing
Any file type up to 10MB
Lightning Fast
Optimized for large files
100% Private
Client-side processing only
URL-Safe Mode
Web-ready Base64 strings
Validation
Detect encoding errors
What is Base64 Encoding?
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It's widely used for embedding images in HTML/CSS, storing binary data in JSON, transmitting data over text-based protocols, and encoding email attachments (MIME). Base64 encoding converts every 3 bytes of binary data into 4 ASCII characters, making it safe for transmission through systems that only support text.
How to Use the Base64 Converter
Using our Base64 converter is simple and secure. To encode text, select "Encode" mode, enter your text in the input field, and the Base64 output appears instantly. To decode, switch to "Decode" mode, paste your Base64 string, and the original text is restored. For files, simply drag and drop any file (up to 10MB) and it will be converted to Base64. All processing happens locally in your browser — your data never leaves your device.
Common Use Cases for Base64
- Embedding Images in HTML/CSS: Convert images to Base64 data URIs to embed them directly in web pages, reducing HTTP requests.
- JSON Data Transfer: Encode binary files as Base64 strings to include them in JSON payloads for APIs.
- Email Attachments: MIME uses Base64 to encode binary attachments for transmission over email protocols.
- Storing Binary in Databases: Convert files to Base64 for storage in text-based database fields.
- URL-Safe Tokens: Create URL-safe Base64 strings for JWT tokens, query parameters, and file names.
Character Encoding Support
Our tool supports multiple character encodings to ensure proper text handling:
- UTF-8: The modern standard, supporting all Unicode characters including emojis (🌍✨)
- ASCII: Basic 7-bit encoding for English text (characters 0-127)
- Latin-1 (ISO-8859-1): Extended ASCII for Western European languages (characters 0-255)
- UTF-16: 16-bit Unicode encoding commonly used in Windows systems
URL-Safe Base64
Standard Base64 uses '+' and '/' characters which have special meaning in URLs. Our URL-safe mode replaces '+' with '-', '/' with '_', and removes padding '=' characters. This makes Base64 strings safe to use directly in URLs, file names, and web tokens without requiring additional URL encoding.
Frequently Asked Questions
What is Base64 encoding used for?
Base64 is a binary-to-text encoding scheme that represents binary data in ASCII string format. It's commonly used for embedding images in HTML/CSS, storing binary data in JSON, transmitting data over text-based protocols, and encoding email attachments (MIME).
Is my data secure when using this tool?
Yes, 100% secure. All encoding and decoding happens locally in your browser. Your data never leaves your device or gets uploaded to any server. We have no access to your files or text.
What file types can I convert to Base64?
You can convert any file type up to 10MB to Base64, including images (JPG, PNG, GIF, WebP, SVG), documents (PDF, DOC, TXT), audio files, video files, and any other binary files.
What is URL-safe Base64?
URL-safe Base64 replaces '+' with '-', '/' with '_', and removes padding '=' characters. This makes Base64 strings safe to use in URLs, filenames, and web tokens without requiring URL encoding.
How do I decode Base64 back to an image?
Switch to "Decode" mode, paste your Base64 string, and click Process. If it's a valid image encoding, you'll see a preview. Click Download to save the decoded image file.
Why does Base64 increase file size?
Base64 encoding uses 4 characters to represent every 3 bytes of binary data, resulting in approximately 33% size increase. This is the trade-off for making binary data safely transmittable as text.