Understand Base64, URL encoding and checksums
Choose the right transformation for text, URL components or comparing file bytes.
Base64 represents bytes as text, URL encoding escapes URL components and a SHA hash summarizes file bytes into a check value. None encrypts your file or automatically verifies that it is trustworthy.
Choose Base64 or Base64URL
Standard Base64 includes + and / and may end with =. Base64URL replaces those two characters with - and _; ToolMint omits trailing padding when encoding. Choose the matching alphabet for decoding.
The tool handles text as UTF-8, including accented characters, Turkish letters and emoji. Encoded binary data such as a whole photo is not necessarily valid UTF-8 text and is rejected when its text encoding is invalid.
Encode a URL parameter
A parameter value Hello world & more becomes Hello%20world%20%26%20more. Encode the value, not the complete address with its separators, or characters such as : and / would change too.
In ToolMint decoding, a plus stays a plus. Spaces are %20. The different plus notation used in form submissions is not automatically treated as a space.
Compare a download using SHA-256
Select the downloaded file in Calculate file checksum and choose the same algorithm as the reference. Paste the complete expected hex value. The result explicitly states whether the values match.
The file name and modification date are not part of the bytes being hashed. Two equally named files can have different hashes; identical bytes under different names have the same hash. Obtain the reference from a source you trust.
Local processing and limits
File checksums require HTTPS or localhost and Web Crypto. Files may be up to 50 MB and are read fully into memory. Processing does not upload the file.
Base64 and URL encoding are reversible representations. A hash is not a way to restore the original content. The page does not save your input as an account or server history.