Converting images to Base64 on a Mac
How to turn an image or a PDF into Base64 on a Mac, how to turn Base64 back into an image, and how to do either to a whole folder at once. Every conversion in B64 runs on your own machine.
Start Here
How to convert an image to Base64 on a Mac
Turn a PNG, JPEG, HEIC, GIF or PDF into a Base64 string on your Mac — plain, as a data URI, or as ready-to-paste HTML, CSS or Markdown.
How to convert Base64 to an image on a Mac
Paste a Base64 string, a data URI or Base64 buried in HTML, CSS or Markdown and get the picture back — free, on your own Mac, with nothing uploaded.
What Base64 is, and when to use it on a Mac
What Base64 encoding is, where it came from, why an encoded file is a third larger, and the cases where turning an image into text is the right answer.
B64 keyboard shortcuts on a Mac
Every keyboard shortcut in B64, grouped by what it does: switching workspaces, loading files, copying and exporting results, and the Inspector.
Encoding images & PDFs
How to convert a PNG to Base64 on a Mac
Encode a PNG to Base64 on your Mac, with transparency intact — as a raw string, a data URI, or a ready-made HTML, CSS or Markdown reference.
How to convert a JPG to Base64 on a Mac
Encode a JPG or JPEG photograph to Base64 on your Mac without re-compressing it — plain, as a data URI, or as HTML, CSS or Markdown.
How to convert a HEIC to Base64 on a Mac
Encode a HEIC or HEIF photo from your iPhone to Base64 on your Mac, and what to check before you embed one somewhere.
How to convert a GIF to Base64 on a Mac
Encode a GIF to Base64 on your Mac with the animation intact — every frame, the timing and the loop count all travel in the bytes.
How to convert an SVG to Base64 on a Mac
Encode an SVG to Base64 on your Mac for a CSS background or a data URI, and what to know about encoding a vector file that is already text.
How to convert a PDF to Base64 on a Mac
Encode a PDF to Base64 on your own Mac — a contract, an invoice or a report — without uploading the document anywhere.
How to convert a screenshot to Base64 on a Mac
Turn a Mac screenshot into Base64 in two keystrokes, without saving a file first and without uploading the picture anywhere.
How to convert a copied image to Base64 on a Mac
Encode an image straight from the clipboard on your Mac — no file to save first, no folder to hunt through afterwards.
Output formats
How to create a data URI from an image on a Mac
Turn an image into a data:image/…;base64 URI on your Mac, with the right MIME type written for you, ready to paste into a browser, an href or a stylesheet.
How to embed an image in HTML on a Mac
Get a complete tag from an image on your Mac — ready for an email template, a single-file page or a self-contained bug report.
How to embed an image in CSS on a Mac
Get a finished background-image rule with the picture inside it, so a stylesheet carries its own assets — produced on your Mac, nothing uploaded.
How to embed an image in Markdown on a Mac
Put a picture inside a Markdown file so a README, a spec or a bug report carries its own screenshots — produced on your Mac, nothing uploaded.
How to wrap Base64 at 64 or 76 columns on a Mac
Turn on MIME-style line wrapping for Base64 output on your Mac, why 76 is the standard width, and when wrapping is not allowed.
How to export Base64 to a text file on a Mac
Write a Base64 result straight to a .txt file on your Mac instead of pushing it through the clipboard — the right move for large files.
How to copy Base64 to the clipboard on a Mac
Copy a complete Base64 result — even a multi-megabyte one — with one keystroke, or have it copied automatically the moment a file is encoded.
Decoding
How to decode a data URI on a Mac
Paste a data:image/…;base64 URI and get the picture back, free, on your own Mac — prefix and all, with nothing to trim off first.
How to extract an image from an HTML img tag on a Mac
Paste a whole tag and get the picture out — free, on your own Mac, with no need to pick the payload out of the attribute first.
How to extract an image from a CSS file on a Mac
Paste a background-image rule with a data URI in it and get the picture back — free, on your own Mac, with the url() wrapper handled for you.
How to decode Base64 inside a Markdown file on a Mac
Get the picture out of a Markdown image reference that carries a data URI — free, on your own Mac, without picking the payload out of the brackets.
How to save a decoded Base64 image on a Mac
Write a decoded Base64 payload to disk as a real image file, with the right extension for what the bytes actually are — free, on your own Mac.
How to preview a Base64 image on a Mac
See what a Base64 payload actually is at full size, with Quick Look, without saving a file and without uploading anything.
How to copy a decoded image to the clipboard on a Mac
Put a decoded Base64 picture straight on the clipboard and paste it into the next app — no file, no folder, nothing uploaded.
Batch conversion
How to convert a folder of images to Base64 on a Mac
Encode every image in a folder to Base64 in one pass on your Mac, each result as its own text file, with anything unsupported listed rather than lost.
How to convert a folder of Base64 files to images on a Mac
Turn a folder of Base64 text files back into image files in one pass on your Mac, with the original names restored automatically.
How to batch convert thousands of images on a Mac
Run a very large Base64 conversion on your Mac without the window stalling — what to expect, how to keep it manageable, and how to stop it.
How to see which files were skipped in a batch on a Mac
Find out exactly which files a batch conversion refused on your Mac and why. Nothing is ever silently dropped from a run.
How to save all batch results to a folder on a Mac
Write every result of a batch run into a new folder in one step — text files for an encode, image files for a decode, names preserved.
How to create a checksum manifest for a batch on a Mac
Write a SHA-256 manifest alongside a batch export on your Mac, so you can prove later that every file in the run came through byte for byte intact.
Details & the Inspector
How to get the SHA-256 checksum of an image on a Mac
Read a SHA-256 checksum of an image, a PDF or a decoded payload from the Inspector, and use it to prove a file arrived intact.
How to see image dimensions and file size on a Mac
Read the pixel dimensions, file size, kind and MIME type of an image or a decoded payload, without leaving the app you are converting in.
How to check the real format of a Base64 image on a Mac
Find out what a Base64 payload actually is, rather than what its data URI claims — and why the two so often disagree.
How to see how much bigger Base64 makes a file on a Mac
Read the exact character count and percentage overhead for a file you have encoded, so you know before you paste it somewhere with a limit.
Large files & troubleshooting
How to encode a large image to Base64 on a Mac
Encode a very large image or document to Base64 on your Mac without the window stalling — paged results, encoding straight to a file, and what to watch.
What to do when Base64 will not decode on a Mac
Work out why a Base64 payload will not turn back into an image — truncation, stray characters, the wrong alphabet — and what to do about each.
How to fix a data URI that will not load on a Mac
Diagnose a data:image URI that shows nothing — a missing prefix, a line break, a wrong MIME type or a truncated payload — and produce a correct one.
B64 settings on a Mac, explained
Every setting in B64 and what it changes: default output format, default wrapping, copy after encoding, checksum manifests, and erasing app data.
How to unlock encoding and batch in B64 on a Mac
What is free, what the one-time purchase unlocks, how to restore it on another Mac, and what happens if you owned the original version.