A .B64 file is typically plain text holding Base64-encoded data, meaning a real file such as a PDF, image, ZIP, or audio has been converted into safe printable characters for transport through systems that might corrupt binary, so when opened in a text editor you’ll see long runs of Base64 symbols—letters, numbers, `+`, `/`, and padding `=`—sometimes wrapped in certificate-style headers or MIME blocks, and decoding restores the original bytes, with common fingerprints like `JVBERi0` for PDFs or `iVBORw0` for PNGs, and remembering that Base64 adds size and offers no encryption or compression.

A .B64 file functions as a safe text wrapper for binary content which is why email systems use Base64 to transport attachments, APIs send documents or signatures as Base64 strings in JSON, developers embed small resources like icons or certificates into HTML/CSS or config files, and migration/backup tools export data that can be pasted or stored easily, with decoding converting the Base64 back into the original file.

Saying a .B64 file stores encoded bytes instead of raw data highlights that you’re looking at a safe, printable character set instead of the true PDF/ZIP/PNG, because binary isn’t reliable in text systems, and Base64 preserves it until you decode it back into the original usable bytes.

You’ll see .B64 files whenever binary content needs a text-safe container, such as email attachments encoded for safe transit, APIs sending images or documents inside JSON, developers embedding icons or certificates into text formats, and export/backup tools creating copy/paste-friendly blobs, with `.b64` acting as a dependable wrapper until decoding restores the real file.

A .B64 file stores Base64 as a transport-safe form of a binary file using an alphabet of letters, numbers, `+`, `/`, and `=`, formatted as wrapped or unwrapped lines and sometimes combined with headers from certificate or email systems, requiring decoding to recover the original PDF, PNG, ZIP, DOCX, or audio file.

A quick way to identify what a .B64 file will become is to check the first Base64 characters, since many file “magic numbers” translate into recognizable prefixes—`JVBERi0` often signals a PDF, `iVBORw0` a PNG, `UEsDB` a ZIP-based file (including Word/Excel/PowerPoint formats), and `/9j/` a JPEG—though headers or wrapping can alter this, it’s still a fast clue for choosing whether to save the decoded output as `.pdf`, `.png`, `.zip`, `.jpg`, or something else.