# deepl api document translation failed: unsupported file type

## TL;DR

Fixes the DeepL document translation failure when the uploaded file type is not supported. Convert to a supported format like docx, pptx, pdf, or html before uploading. Use when the API rejects the file type. Not for quota errors.

## The error

```text
{"message":"Unsupported file type. Supported types: docx, pptx, pdf, html, txt."}
```

## Fix it

### Step 1: Confirm the file type

```bash
file upload/report.pages | head -2
```

Expected: You see the actual file type the API received.

### Step 2: Convert to a supported format

```bash
node -e "console.log('export the document to docx or pdf, then upload the converted file')"
```

Expected: You have a supported file ready.

### Step 3: Upload the converted file

```bash
node -e "console.log('submit the docx and confirm the translation job starts')"
```

Expected: The document translation job starts successfully.

## When to use this

- DeepL rejects a document upload for its file type
- The API lists supported types in the error

## When NOT to use this

- The API returns 456, that is a quota problem
- The translated document has broken formatting, check the source layout

## Tool and version compatibility

- DeepL API document translation endpoint
- Free and Pro plans with document support

## Variant phrasings

### file extension is supported but still rejected

The file content does not match its extension. Re-export it cleanly.

### large pdf fails

Scanned PDFs are images, not text. OCR the PDF first.

## Why it happens

DeepL's document endpoint parses specific office formats. Anything outside that list cannot be parsed into translatable segments, so the API rejects it up front instead of producing a corrupt translation.

## Edge cases

- Password-protected files are rejected even in supported formats
- Files over the size limit fail with a different error; check both
- Translated layout can shift for complex source formatting

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_n3iQJmO7nvuLt3B0covR2g