BaseToBase Extension
Introduction
In the world of digital communication, the conversion of numbers between different formats is often a necessity. Because of the lack of these conversions in one place, the "BaseToBase" extension is here to simplify this process for you in Appinventor compatibles. This extension is designed to convert numbers from one base into another and vice versa. Whether you're working with hexadecimal, binary, integer, char codes, octal, ASCII (text), or Base64, this extension has you covered. Use it in any project, but keep the credits.
Technical info
Extension

Current extension version: V15 (download map)
First publicly published version.  Minimum Apilevel: 1
 Permissions: No extra (Manifest.xml) permissions needed
 Binary extension license: The 3Clause BSD License (following at the end of this page)
Example

Extension V15 APK  Ready to run
Functions
The "BaseToBase" extension offers a variety of functions to help you with number conversions.
AsciiToHex
 Description: Convert Text (ASCII) to Hexadecimal.
 Input: Text (e.g., "Hello!").
 Output: Hexadecimal representation (e.g., "48656c6c6f21").
HexToAscii
 Description: Convert Hexadecimal to Text (ASCII).
 Input: Hexadecimal number (e.g., "48656c6c6f21").
 Output: Text (e.g., "Hello!").
Base64ToHex
 Description: Convert Base64 to Hexadecimal.
 Input: Base64encoded string (e.g., "SGVsbG8h").
 Output: Hexadecimal representation (e.g., "48656c6c6f21").
HexToBase64
 Description: Convert Hexadecimal to Base64.
 Input: Hexadecimal number (e.g., "48656c6c6f21").
 Output: Base64encoded string (e.g., "SGVsbG8h").
BinaryToHex
 Description: Convert Binary to Hexadecimal.
 Input: Binary number (e.g., "010010000110010101101100011011000110111100100001").
 Output: Hexadecimal representation (e.g., "48656c6c6f21").
HexToBinary
 Description: Convert Hexadecimal to Binary.
 Input: Hexadecimal number (e.g., "48656c6c6f21").
 Output: Binary representation (e.g., "010010000110010101101100011011000110111100100001").
IntegerToHex
 Description: Convert Integer to Hexadecimal.
 Input: Integer number (e.g., "79600447942433").
 Output: Hexadecimal representation (e.g., "48656c6c6f21").
HexToInteger
 Description: Convert Hexadecimal to Integer.
 Input: Hexadecimal number (e.g., "48656c6c6f21").
 Output: Integer number (e.g., "79600447942433").
OctalToHex
 Description: Convert Octal to Hexadecimal.
 Input: Octal number (e.g., "2206255433067441").
 Output: Hexadecimal representation (e.g., "48656c6c6f21").
HexToOctal
 Description: Convert Hexadecimal to Octal.
 Input: Hexadecimal number (e.g., "48656c6c6f21").
 Output: Octal representation (e.g., "2206255433067441").
Helper blocks
XtensionInfo
 Description & Output: Extension version info & copyright.
XtensionUUID
 Description & Output: Extension UUID
Example code block
Input: "Hello!"
Extension UUID
 f9c820d040544e99a0e868abba7e653a
FAQ  Frequently Asked Questions
 Why do I need an input integer as string?
Because the Biginteger library is used. Those big numbers do not fit in the standard java integer. On the other hand, you can use real big numbers. The limit is 32 * 2^321 bits for BigInteger or about 2^(4 billion). The output is also an integer as string.
Copyrights & License

Eric M. Kok (appsbeheerder)
For the (compiled Java source) BaseToBase extension the The 3Clause BSD License is applicable.The 3Clause BSD License
BaseToBase, Copyright 2023 Eric M. Kok (appsbeheerder)Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
 Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
 Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
 Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.