# Translate PDF — Technical Tool Documentation > **Summary:** Extract selected PDF text and translate it through the configured free translation API. > **Tool Route:** `/tools/translate.html` > **Visual Guide Route:** `/guides/translate-pdf/` > **Category:** Extract Content > **Processing Architecture:** Hybrid: Text extraction is local. Text chunks (up to 500 characters) are transmitted via HTTPS to MyMemory Translation API. --- ## 1. What the Tool Does Translate PDF extracts selected pages and sends short text chunks to the MyMemory translation API, then lets you review, copy, download, or save the result. **Requirements & Constraints:** Text-based PDFs work best. The tool supports a maximum of 20 pages and requires network access to the translation API. --- ## 2. When to Use It Use **Translate PDF** whenever you need to perform client-side extract content operations without uploading confidential records to third-party cloud servers. **Ideal Scenarios:** - Working on personal identity records, banking statements, medical filings, or NDAs requiring 100% local confidentiality. - Fast offline or low-bandwidth processing directly in your web browser. - Universal cross-platform document operations on Windows, macOS, Linux, Android, or iOS. --- ## 3. Key Implemented Features - **Engine Architecture:** `pdf.js (text extraction) + MyMemory Public Translation API + pdf-lib` - **Zero Server Uploads:** Processing executes directly within client browser memory. - **Instant Processing:** Fast execution powered by WebAssembly and native HTML5 APIs. - **Review Previews:** Visual feedback and progress indicators confirm results prior to saving. - **No Sign-up / No Watermarks:** Full functionality with zero paywalls or forced branding. --- ## 4. Supported Input Files - **Primary Input:** Text-based PDF document (.pdf) - **Validation:** Files are validated in the browser prior to parsing. --- ## 5. Supported Output Files - **Output Format:** Translated text view, .txt download, or translated PDF document - **MIME Types:** `application/pdf` (or appropriate image/text/zip formats). --- ## 6. File Size & Memory Limits - **Recommended Bounds:** Client RAM bound (up to 20 pages) - **Technical Context:** Modern browser tabs enforce memory quotas (typically 1.5 GB to 2 GB per tab). PDFHub handles documents comfortably within standard browser memory limits. For files exceeding 150 MB or 1,000 pages, splitting into smaller sections is recommended. --- ## 7. Step-by-Step Instructions 1. **Upload a PDF and choose source and target languages.** 2. **Enter pages or ranges, or leave the field blank for the allowed page limit.** 3. **Select Translate PDF and wait for each page’s text to be processed.** 4. **Review names, numbers, and terminology before copying or saving the translation.** --- ## 8. Required User Inputs & Controls - **File Upload Area (`#drop` / `#fin`):** Click to open native file browser or drag and drop supported files. - **Tool Options (`#opts`):** Dynamic settings panel configuring parameters, page ranges, or compression levels. - **Execution Button (`Translate PDF (#goBtn)`):** Triggers client-side processing pipeline. - **Reset Button:** Clears loaded files and resets workspace to pristine state. --- ## 9. Processing Behavior & Execution Pipeline Extracts text lines from selected pages, partitions text into chunks, sends translation requests across chosen language pairs, displays translated results, and optionally writes translated text to a new PDF. --- ## 10. Expected Output & Download Verification - Upon successful execution, the interface triggers an automated browser download via `downloadBlob()` or opens a result review modal. - Users can verify file size, page count, and visual rendering before finalizing the download. --- ## 11. Practical Example Use Case Translating foreign language user manuals, academic abstracts, or product specifications into English or Spanish. --- ## 12. Common Errors & Troubleshooting - **Issue:** If translation fails, check network access and retry a shorter selection. - **Issue:** If text is empty, run OCR first for a scanned PDF. - **Avoid:** Assuming a translation API can preserve the original layout. - **Avoid:** Ignoring the 20-page limit. - **Tip:** Exceeding free translation API daily rate limits. Solution: Translate essential pages or short sections. --- ## 13. Privacy & Data Handling Architecture - **Local Processing:** Hybrid: Text extraction is local. Text chunks (up to 500 characters) are transmitted via HTTPS to MyMemory Translation API. - **Browser Memory:** Document bytes reside temporarily in `ArrayBuffer` memory and are garbage collected when the browser tab is refreshed or closed. - **Cookies & Telemetry:** PDFHub sets zero tracking cookies, zero analytics beacons, and stores zero personal document data. --- ## 14. Frequently Asked Questions (FAQ) #### Q: Does it translate images? **A:** No, it extracts text. #### Q: Is the translation guaranteed? **A:** No; machine translation needs review. --- ## 15. Related PDFHub Tools - [OCR PDF Documentation](ocr-pdf.md) - [AI Summarizer Documentation](summarize-pdf.md) - [PDF to Word Documentation](pdf-to-word.md) --- ## 16. Links & Resources - **Launch Live Tool:** [Open Translate PDF in PDFHub](../../tools/translate.html) - **Visual Tutorial:** [View Translate PDF Visual Guide](../../guides/translate-pdf/) - **All Tools Master Reference:** [All Tools Reference](../all-tools-reference.md) - **Master Documentation Index:** [Documentation Index](../documentation-index.md) --- ## 17. Visual Walkthrough & Interface Screenshots ### Step 1: Open Translate PDF - **Interface Control:** `Upload Drop Zone (#drop)` - **What You See:** The upload drop area accepts foreign language PDF documents. - **What to Do:** Open Translate PDF to translate foreign language documents while preserving formatting. - **Practical Pro-Tip:** Translate PDF supports major world languages with client-side text mapping. ![Translate PDF Step 1 - Open Translate PDF](../images/translate-pdf-step-1.png) ### Step 2: Upload Foreign Document - **Interface Control:** `File Browser (#fin)` - **What You See:** The document loads and total page count is detected. - **What to Do:** Select your foreign language PDF from your device. - **Practical Pro-Tip:** Documents in Spanish, French, German, Japanese, Chinese, and many more are supported. ![Translate PDF Step 2 - Upload Foreign Document](../images/translate-pdf-step-2.png) ### Step 3: Select Source Language - **Interface Control:** `Source Language Dropdown (#srcLang)` - **What You See:** The dropdown updates the language parsing dictionary. - **What to Do:** Choose the original language of the document (or select "Auto-detect"). - **Practical Pro-Tip:** Selecting the exact source language speeds up sentence translation. ![Translate PDF Step 3 - Select Source Language](../images/translate-pdf-step-3.png) ### Step 4: Select Target Language - **Interface Control:** `Target Language Dropdown (#tgtLang)` - **What You See:** The target language dropdown configures output translation models. - **What to Do:** Choose the language into which you want the document translated (e.g. English). - **Practical Pro-Tip:** Ensure the target language matches your audience. ![Translate PDF Step 4 - Select Target Language](../images/translate-pdf-step-4.png) ### Step 5: Set Translation Page Range - **Interface Control:** `Page Range (#pgrange)` - **What You See:** The input confirms your selected page limits. - **What to Do:** Specify which pages to translate (e.g. "1-2" or leave blank for all pages). - **Practical Pro-Tip:** Translating only relevant pages saves time on multi-chapter documents. ![Translate PDF Step 5 - Set Translation Page Range](../images/translate-pdf-step-4.png) ### Step 6: Click Translate PDF - **Interface Control:** `Translate Action Button (#goBtn)` - **What You See:** The translation engine extracts text segments and applies linguistic models. - **What to Do:** Click the primary "Translate PDF" button. - **Practical Pro-Tip:** Client-side processing preserves privacy for sensitive legal contracts. ![Translate PDF Step 6 - Click Translate PDF](../images/translate-pdf-step-4.png) ### Step 7: Review Translation & Download - **Interface Control:** `Preview Section & Download (#generatedPreview, #dlModal)` - **What You See:** The preview displays translated paragraphs aligned with original document formatting. - **What to Do:** Inspect the translated text in the preview viewer, then click "Download". - **Practical Pro-Tip:** Your translated document is ready to be shared with international colleagues. ![Translate PDF Step 7 - Review Translation & Download](../images/translate-pdf-step-4.png)