How to copy Base64 to the clipboard on a Mac
You can do this with B64 in one keystroke, or in none at all. Here is how copying works and how to stop having to ask for it.
Most of the time the Base64 is going straight into something else: a field, a file you already have open, a message. The clipboard is the shortest path, and B64 is built so that path is one keystroke or zero.
Copy the result
Encode the file
Load your image or PDF in Encode (⌘1).
Pick the format
Whatever is selected is what gets copied — the raw string, the data URI, the
<img>tag, the CSS rule or the Markdown reference.Copy
Press ⇧⌘C, or click Copy. The complete result goes to the clipboard.
A long result is displayed in pages so the window stays responsive. Copy is unaffected: it always takes the whole string, whichever page is on screen.
Make it automatic
Switch on copy after encoding in B64 ▸ Settings… ▸ General. The result lands on the clipboard the moment a file is encoded, so the whole interaction becomes: drop the file in, go and paste it.
Combined with a default output format, that removes every decision from the common case. Combined with Paste Image (⇧⌘V), it means a screenshot on your clipboard becomes a Base64 string on your clipboard in a single keystroke.
Copying very large results
Several megabytes of text will go on the clipboard, but it is worth asking whether it should. If the destination is a file, Export… (⌘E) writes it directly and skips the round trip entirely.
Two other things happen to very large clipboard contents in the wild: some applications are slow to accept a paste that size, and some — chat clients and web forms in particular — silently rewrite whitespace. Where that matters, move a file rather than a paste.
Copying the picture instead of the string
In Decode, Copy Image puts the decoded picture on the clipboard as an image — ready to paste into a document or a message, with no file written to disk. See how to copy a decoded image to the clipboard.
Troubleshooting
The paste is missing the beginning or the end
The copy took everything, so the loss happened at the far end: a field with a length limit, or a client that trimmed it. Check the character count in the app against what arrived, and export a file instead if they disagree.
The pasted string has line breaks I did not ask for
Something in between rewrapped it. Export to a .txt file and move the file.
I copied the wrong shape
The format menu decides what Copy takes. Switch it and copy again — there is no need to re-encode.
Frequently asked questions
Does Copy take the whole result if it is shown in pages?
Yes. Paging is only a display choice; Copy always takes the complete string.
Can the result be copied automatically?
Yes — switch on copy after encoding in Settings and the result lands on the clipboard as soon as a file is encoded.
Is there a limit to how much I can copy?
Not in the app, but very large clipboard contents are slow to paste in some applications and are sometimes rewritten by chat clients and web forms. Export a file instead when that matters.
How do I copy the picture rather than the string?
In Decode, use Copy Image — it puts the decoded picture on the clipboard as an image.