Files, Binary & Compression
Convert binary files with an explicit choice of text representation.
Drop or choose one file here (up to 600,000 bytes).
No file selected.
Files and text stay in this browser; conversion makes no network requests.
MIME is a declaration, not verified file identity. Data URLs use the header MIME type; raw data uses this field.
Standard Base64 (+ /) only. Decoding accepts exact or missing padding and rejects nonzero unused trailing bits. Data URLs require data:type/subtype;base64,payload without parameters or percent encoding.
File and decoded output: 600,000 bytes. Encoded input: 1,000,000 UTF-16 units including header and whitespace. Empty files and manually converted empty raw input are valid.
Image preview is off.
Choose a file, paste Base64 or preview the example.
Reverse previews the complete result for the other direction. Switching direction retains both inputs; Clear removes both after confirmation.
File to Base64 prepares small binary attachments for interfaces that accept text. This file Base64 converter reads bytes directly, so PDFs, archives and images do not need to be valid UTF-8. The reverse direction restores those bytes without a text decoding step.
For Base64 to File, choose raw input or a complete Data URL explicitly. MIME metadata describes the intended type; changing it does not convert the file. Inspect the byte count before exporting, especially when the visible result is shorter than the complete encoded value.
File to Base64 lets a small attachment cross a text-only boundary and return as a file. The binary download uses the full byte sequence without first interpreting it as text. Null bytes and non-UTF-8 sequences remain part of the file.
Decoding successfully does not imply that the content should be rendered. Preview starts off and only supports bounded static PNG, JPEG and WebP files. A blocked preview does not prevent downloading the decoded file.
Raw Base64 has no header. Select Data URL for data:type/subtype;base64,payload without parameters. Decoding takes MIME from that header, while raw input uses the MIME field. The tool does not silently switch formats.
Automatic conversion waits 350 ms after changes. Turn it off to run manually, including with Ctrl/Cmd+Enter. Changes make old results stale immediately, blocking copy and download until the next successful conversion.
Replacing a file, loading the example, clearing and reversing show a preview with byte and text counts. Apply commits the replacement. Undo restores the previous inputs, options and result once, including its previous freshness state.
Copy provides encoded text, TXT saves that representation and Download file exports the bytes. The display stops at 20,000 text units; all three export actions use the complete current result.
The result shows canonical standard Base64 with required = padding. Its raw or Data URL representation follows your selected format. The padding switch affects encoding only; decoding does not preserve an unpadded spelling.
Ignoring whitespace removes only SP, TAB, CR and LF from encoded input. Other space characters remain invalid. The result reports how many allowed whitespace units were removed.
Choose a filename and MIME metadata for the download. Neither an extension change nor a new MIME declaration converts the file format or proves that the bytes match the declared type.
Raw Base64 contains no type metadata. File to Base64 can add a Data URL header during encoding. When decoding, select the Data URL representation only for a complete header; for bare data, choose raw and enter MIME separately.
The encoded character count is not the file size: the header and padding contribute differently. As a browser alternative, decode the data URI here and read the byte count. Supported static image previews also show pixel dimensions. This page does not inspect JavaScript source.
Possible causes include passing the header to a raw decoder or damaged padding; the exact cause needs the original code. Check the full Data URL in the matching format here. Exact or omitted padding is accepted, partial padding is not. This is an input check, not a Python or KineticJS debugger.
Choose the decoding direction, select the input format and set a filename. After conversion, Download file saves the bytes directly. File to Base64 provides this browser alternative to writing a file in code; it does not debug a program’s file handling.
Base64 represents arbitrary bytes, so the string alone does not prove a file type. MIME is also only a declaration. The limited image preview checks supported signatures but does not provide general format detection or a security analysis.
Missing an edge case?
Start File to Base64 with a small file. Check the representation and byte count, review the reverse operation before applying it, then export the full result.