UToolios synthetic Base64 fixtures, 3 November 2026. Reuse permitted.
checkmark.txt: E2 9C 93 (UTF-8), no newline; standard Base64 4pyT.
two-bytes.bin: FB FF; standard Base64 +/8=; unpadded URL-safe -_8.
These bytes do not establish a complete file format.
Guide: https://utoolios.com/guides/base64-binary-vs-text