Base64 File Inspector

Paste raw Base64 from API payloads and instantly see whether it's an image, PDF, CSV, or text — then download the decoded file locally.

Input

Drop a .txt file containing Base64

Preview

File type: — Size: —

Preview will appear here after decoding.

How This Tool Works

Whitespace and quotes are stripped from your input. If a Data URI prefix is present, its MIME type is used; otherwise the tool inspects magic bytes after atob() decoding (PDF, PNG, JPEG, GIF, WebP, ZIP). Text-like content is shown in a scrollable <pre> block with basic JSON/XML highlighting. Images render in <img>; PDFs load in a local <iframe> via a Blob URL.

Key Benefits

  • Instant visual confirmation: See what an API Base64 field actually contains without writing a script.
  • 100% local: Uses atob, Uint8Array, Blob, and URL.createObjectURL only — nothing is uploaded.
  • One-click download: Save the decoded file with the correct extension inferred from content.

Practical Use Cases

  • API debugging: Preview a Base64-encoded invoice PDF or profile photo returned in a JSON response.
  • Integration testing: Verify encoded attachments from email or document APIs before wiring them into your app.
  • Security review: Inspect suspicious Base64 blobs from logs without executing them on a server.

Frequently Asked Questions

What if the Base64 string is truncated?

The tool pads missing = characters when possible, but severely truncated data will fail decode with a clear error message.

Can it decode UTF-8 text?

Yes. Plain text and JSON/XML are detected by printable-byte heuristics or magic bytes and displayed as UTF-8.