Encode text to Base64 or decode Base64 strings back to text. Handles Unicode and special characters.
Files processed securely via encrypted connection. Automatically deleted after processing. Never stored or shared.
Base64 encoding converts binary data into a string of printable ASCII characters. This allows binary content to be safely transmitted through text-based systems like email, HTML attributes, JSON payloads, and URLs without corruption or misinterpretation of special characters.
Base64 takes every 3 bytes of input (24 bits) and splits them into 4 groups of 6 bits each. Each 6-bit group maps to one of 64 printable characters. This is why Base64 output is approximately 33% larger than the original — 3 bytes become 4 characters. The equals sign padding at the end indicates the input length was not a multiple of 3.
Base64 is encoding, not encryption. Anyone can decode a Base64 string instantly with no key required. Never use Base64 to hide sensitive data. Use it only to safely transmit binary data in text contexts.
Web developers encounter Base64 encoding regularly in several contexts. Data URLs used to embed images and fonts directly in HTML or CSS use Base64 encoding. This technique eliminates an HTTP request for small images like icons and logos, potentially improving page performance. HTTP Basic Authentication sends credentials as Base64-encoded username and password in the Authorization header. JSON Web Tokens use a URL-safe Base64 variant to encode their header and payload sections in all modern authentication systems.
Base64 encoding increases data size by approximately 33 percent. Every 3 bytes of binary data becomes 4 ASCII characters. A 100KB PNG image encoded in Base64 becomes approximately 133KB. For small images like icons and logos under 5KB, this overhead is acceptable and the elimination of an HTTP request is a net performance gain. For larger images, the size increase outweighs the benefit and it is more efficient to serve them as separate files with standard HTTP caching.
From university students working on assignments to HR professionals processing documents, from small business owners managing invoices to software developers working with data formats, Quickly.fit tools are used daily by people across every profession and every industry. The common thread is the need for reliable, fast, professional results without the cost and complexity of dedicated desktop software subscriptions that are not justified for occasional or moderate use.
Quickly.fit is actively maintained and regularly updated to ensure compatibility with the latest file formats, browser standards, and security requirements. When browsers update their capabilities, our tools are updated to take advantage of improvements. When new file format versions become common, our converters are updated to handle them. User feedback directly shapes what gets improved next. This ongoing investment in quality is what separates a genuinely useful tool from one that works when first built but gradually becomes unreliable as the web evolves around it.