Suppose we have “hi” as our string, the ASCII equivalent being: 104 ( h), 105 ( i). The result is an ASCII-readable string that can be safely transmitted and received.įor the sake of simplicity, we’ll use a short string to demonstrate the encoding process. Starting with binary information, base 64 splits a binary string into 6-bit groups (note: each zero or one in a binary string is one bit) of three bytes. Java, Python, JS) include built-in functions to facilitate the conversion of base64 encoded information and binary data, the algorithm used to perform the conversion is relatively simple. On top of being used for safely encoding image/media data (you may have seen images on the web encoded in the following format: data:image/png base64,(.)), it is used for SSL certificates, email transmissions, and virtually any transfer of information that requires special (control) characters to be escaped. In other words, any base-64 string can be decoded, as long as the string was encoded using a standard set of characters (which the decoder can also understand). Another important distinction is that base 64 does not encrypt any information - it uses a “standard” table of characters to encode and decode information. On base 64 encoded data, the resultant string is always larger than the original (i.e. It achieves this through the conversion of binary data and a “lookup table” - data is eventually made in a stream of ASCII characters, which can then be transmitted and decoded. Here are the two possible methods.Base64 encoding is a format designed to prevent communication “mishaps” during the transfer of binary information. the second one is to convert the UTF-16 DOMString to an UTF-8 array of characters and then encode it.the first one is to escape the whole string and then encode it.There are two possible methods to solve this problem: Since DOMStrings are 16-bit-encoded strings, in most browsers calling window.btoa on a Unicode string will cause a Character Out Of Range exception if a character exceeds the range of a 8-bit ASCII-encoded character. StringView – a C-like representation of strings based on typed arrays.Rewriting atob() and btoa() using TypedArrays and UTF-8.working with other Unicode encodings, different from default JavaScript's UTF-16 DOMStrings,.creating a collection of methods for such string-like objects (since now: stringViews) which work strictly on array of numbers rather than on immutable JavaScript strings,.array of characters codes - ArrayBufferView in JavaScript) based upon the JavaScript ArrayBuffer interface, creating a C-like interface for strings (i.e.URIScheme List of Mozilla supported URI schemes StringView In this article is published a library of ours whose aims are: The "Unicode Problem" In most browsers, calling btoa() on a Unicode string will cause a Character Out Of Range exception. btoa() Creates a base-64 encoded ASCII string from a "string" of binary data. atob() Decodes a string of data which has been encoded using base-64 encoding. Base64 Wikipedia article about Base64 encoding. Documentation data URIs data URIs, defined by RFC 2397, allow content creators to embed small files inline in documents. If you want to work on ArrayBuffers, please, read this paragraph. On the contrary, the btoa() function creates a base-64 encoded ASCII string from a "string" of binary data.īoth atob() and btoa() work on strings. The atob() function decodes a string of data which has been encoded using base-64 encoding. In JavaScript there are two functions respectively for decoding and encoding base64 strings: Base64 is commonly used in a number of applications including email via MIME, and storing complex data in XML. This is to ensure that the data remain intact without modification during transport. The term Base64 originates from a specific MIME content transfer encoding.īase64 encoding schemes are commonly used when there is a need to encode binary data that needs to be stored and transferred over media that are designed to deal with textual data. Base64 is a group of similar binary-to-text encoding schemes that represent binary data in an ASCII string format by translating it into a radix-64 representation.
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