Base64 to File Converter

Decode a Base64 string and download it as a file. Supports all file types with automatic MIME type detection and custom filenames.

Last Updated: August 2026
100% Client-Side — Your data never leaves your device

Paste a Base64 string (with or without a data: prefix) and download it as a file. The MIME type is auto-detected from data URIs.

Why this tool is safe

Your data never leaves your device — everything runs in your browser.

No server uploads. Other tools send your files to their servers. Ours don't.
Zero tracking of content. We never see, store, or log anything you convert.
Works offline. Once loaded, the tool works without an internet connection.

Base64 to File in Code

Decode Base64 strings and save them as files programmatically.

Python
import base64

# Decode Base64 string to file
def base64_to_file(b64: str, output_path: str):
    # Strip data URI prefix if present
    if "," in b64:
        b64 = b64.split(",", 1)[1]
    with open(output_path, "wb") as f:
        f.write(base64.b64decode(b64))

# Usage
base64_to_file("iVBORw0KGgo...", "image.png")

# Decode with MIME type detection
def base64_to_file_safe(b64: str, output_path: str):
    import re
    # Extract MIME type from data URI
    mime_match = re.match(r"data:([^;]+)", b64)
    if mime_match:
        mime = mime_match.group(1)
        print(f"Detected MIME: {mime}")
    if "," in b64:
        b64 = b64.split(",", 1)[1]
    with open(output_path, "wb") as f:
        f.write(base64.b64decode(b64))

Frequently Asked Questions

Search below or browse through our most commonly asked questions.

Paste your Base64 string into the input area. The tool will automatically detect the file type if it contains a data URI scheme. You can then download the decoded file directly.
Any valid Base64 string can be decoded into a file. This includes images, documents (PDF, DOCX), audio, video, and archives (ZIP, TAR).