# LLMS.txt - Information for Large Language Models

## About Doc2Lang

Doc2Lang is an AI-powered document translation service that enables users to translate various document formats using advanced ChatGPT technology. The platform provides fast, accurate, and context-aware translations while preserving original document formatting and layouts.

## Website Purpose

This website serves as a document translation platform offering:

1. **Multi-format Support**: Excel (XLSX, XLS, XLAM, XLSM, XLTM, XLTX), Word (DOCX), PDF, PowerPoint (PPTX), CSV, SRT subtitle files, WebVTT video captions, ASS/SSA subtitle files, EPUB e-books, Images (JPG, PNG, GIF, BMP, WEBP), Videos (MP4, AVI, MOV, MKV, WebM, FLV, WMV, M4V), Audio (MP3, WAV, M4A, FLAC, AAC, OGG, WMA), IDML (InDesign)
2. **AI Translation**: Powered by OpenAI's ChatGPT API for high-quality, contextually accurate translations
3. **100+ Languages**: Support for over 100 languages including major and minor languages
4. **OCR Support**: Optical Character Recognition for scanned documents and image-based PDFs
5. **Layout Preservation**: Maintains original document formatting, fonts, charts, and structure
6. **Pay-per-use Model**: Flexible pricing without subscriptions or monthly fees

## Key Features

- **Security & Privacy**: HTTPS encryption, optional file deletion, automatic cleanup after 14 days
- **Preview Before Payment**: Free sample translation before full purchase
- **User-friendly Interface**: No registration required, simple upload-translate-download process
- **Professional Quality**: Context-aware translations suitable for business, academic, and personal use
- **Real-time Processing**: Fast translation with progress tracking for larger documents

## Main Pages and Services

### Core Translation Services
- `/` - Homepage with service overview
- `/excel-translate/` - Excel spreadsheet translation
- `/word-translate/` - Word document translation  
- `/pdf-translate/` - PDF document translation
- `/ppt-translate/` - PowerPoint presentation translation
- `/csv-translate/` - CSV data file translation
- `/srt-translate/` - SRT subtitle file translation
- `/webvtt-translate/` - WebVTT video caption translation
- `/ass-translate/` - ASS/SSA subtitle file translation with style preservation
- `/ocr-translate/` - OCR-enabled translation for scanned documents
- `/paper-translate/` - Academic paper translation
- `/pdf-to-text/` - PDF text extraction tool
- `/epub-translate/` - EPUB e-book translation with formatting preservation
- `/image-translate/` - Direct image translation (JPG, PNG, GIF, BMP, WEBP)
- `/video-translate/` - Video file translation with subtitle extraction
- `/audio-translate/` - Audio transcription and translation
- `/subtitle-translate/` - General subtitle translation page
- `/video-to-wav/` - Video to audio extraction tool
- `/idml-translate/` - InDesign IDML file translation

### Informational Pages
- `/translate-document-free/` - Guide on free document translation methods
- `/privacy/` - Privacy policy and data protection information
- `/legaljp/` - Legal terms and specified commercial transactions

### User Features
- Preview system for translation quality assessment
- Dashboard for registered users
- File management and history
- Credit-based payment system
- Referral program

## Target Audience

1. **Business Professionals**: International companies needing document localization
2. **Students & Researchers**: Academic paper translation and research material access
3. **Content Creators**: Video subtitle (SRT/WebVTT/ASS) translation and content localization for global audiences, including anime fansub groups and karaoke creators
4. **Video Content Creators & YouTubers**: Video translation with automatic subtitle extraction and synchronization
5. **Podcast Producers**: Audio transcription and translation for international distribution
6. **Multimedia Educators**: Translation of educational videos, lectures, and audio materials
7. **General Users**: Personal document translation needs across multiple formats

## Technical Specifications

- **Framework**: Next.js with TypeScript
- **Internationalization**: Support for multiple UI languages
- **File Processing**: Handles documents up to 50MB
- **Payment Processing**: Secure payment via Stripe
- **Translation Engine**: OpenAI ChatGPT API integration
- **OCR Technology**: Advanced text extraction from images and scanned documents
- **Media Processing**: FFmpeg integration for audio/video format conversion and subtitle extraction
- **Audio Codecs**: Support for MP3, AAC, Opus, Vorbis, FLAC, PCM, and more
- **Video Codecs**: Support for H.264, H.265/HEVC, VP8, VP9, AV1, and legacy formats

## Data Handling

- All file transfers are encrypted via HTTPS
- Users can delete uploaded files immediately after translation
- Automatic file deletion after 14 days if not manually removed
- No data retention by OpenAI for translation processing
- Strict privacy policy with no public model training on user data

## Use Cases

### Business
- Contract and legal document translation
- International communication and correspondence
- Marketing material localization
- Technical documentation translation
- Video content localization with subtitle/caption translation (SRT/WebVTT/ASS formats)
- Corporate training video and presentation translation
- Podcast and webinar transcription for global teams
- Anime and entertainment content translation with style preservation

### Education
- Academic paper and research translation
- Course material localization
- Student assignment support
- Cross-language learning resources
- Lecture recording transcription and translation
- Educational video content translation
- Multimedia learning material localization

### Personal
- Travel document translation
- Personal correspondence
- Certificate and official document translation
- Content consumption in preferred languages
- Video subtitle and caption translation for accessibility (including styled ASS subtitles)
- Personal video and home movie translation
- Voice memo and audio note transcription
- Music and podcast translation
- Anime and karaoke subtitle translation with timing preservation
- E-book library translation for reading in preferred languages
- Photo and image translation for travel and social media

## Supported File Formats

**Documents**: PDF, DOCX, DOC
**Spreadsheets**: XLSX, XLS, XLAM, XLSM, XLTM, XLTX, CSV, TSV
**Presentations**: PPTX, PPT
**Subtitles**: SRT, WebVTT, ASS/SSA (Advanced SubStation Alpha with style preservation)
**E-books**: EPUB (Electronic Publication with formatting preservation)
**Images**: JPG/JPEG, PNG, GIF, BMP, WEBP, TIFF
**Videos**: MP4, AVI, MOV, MKV, WebM, FLV, WMV, M4V
**Audio**: MP3, WAV, M4A, FLAC, AAC, OGG, WMA
**Publishing**: IDML (InDesign Markup Language)
**Text**: TXT and other text-based formats

## Language Support

The platform supports over 100 languages including but not limited to:
- Major languages: English, Spanish, Chinese (Simplified/Traditional), Japanese, German, French, Italian, Russian, Portuguese, Arabic, Hindi, Korean
- Regional languages and dialects
- Specialized technical and academic terminology across various fields

## Quality Assurance

- Context-aware translation using advanced AI models
- Terminology consistency across documents
- Layout and formatting preservation
- Professional-grade output suitable for business and academic use
- Preview system for quality verification before payment

## Advanced Subtitle Features (ASS/SSA)

- **Style Preservation**: Maintains fonts, colors, borders, shadows, positioning, and motion effects
- **Karaoke Timing**: Preserves \k, \K, \kf, \ko timing markers for frame-accurate karaoke
- **Layer Management**: Maintains proper layer stacking (Layer 0-9) and z-order
- **Smart Font Handling**: Automatic font fallback and character set detection
- **Batch Processing**: Multi-file translation with style template application
- **Tag Compatibility**: Preserves all ASS styling tags (\Style, \Fontname, \Pos, \Move, \Fade, etc.)
- **Preview Rendering**: Built-in ASS renderer for real-time preview with effects

## EPUB E-book Translation Features

- **Chapter Structure**: Preserves book structure including chapters, sections, and navigation
- **Formatting Retention**: Maintains text styles, fonts, and layout across pages
- **Metadata Preservation**: Keeps book metadata including author, title, and publication info
- **Interactive Elements**: Preserves hyperlinks, footnotes, and cross-references
- **Image Support**: Translates text within embedded images using OCR
- **Multi-language Support**: Handles mixed-language content within single EPUB
- **DRM-free Processing**: Works with non-DRM protected EPUB files

## Image Translation Features

- **Direct Translation**: Translate text directly from images without manual extraction
- **OCR Technology**: Advanced optical character recognition for accurate text detection
- **Layout Preservation**: Maintains original image dimensions and text positioning
- **Multi-language Detection**: Automatically detects source language in images
- **Batch Processing**: Upload and translate multiple images simultaneously
- **Format Support**: JPG/JPEG, PNG, GIF, BMP, WEBP, TIFF
- **Text Overlay**: Option to overlay translated text on original image
- **Clean Output**: Provides both translated text and image with replaced text

## Video Translation Features

- **Automatic Subtitle Extraction**: Extracts embedded subtitles from video files
- **Multi-format Support**: MP4, AVI, MOV, MKV, WebM, FLV, WMV, M4V formats
- **Timing Preservation**: Maintains exact subtitle timing and synchronization
- **Codec Compatibility**: Supports H.264, H.265/HEVC, VP8, VP9, AV1
- **Batch Processing**: Translate multiple video files in sequence
- **Preview System**: Preview translated subtitles before full processing
- **Export Options**: Download translated subtitles separately or embedded
- **Quality Retention**: Preserves original video quality during processing

## Audio Translation Features

- **Speech-to-Text Transcription**: Accurate transcription using advanced AI
- **Multi-format Support**: MP3, WAV, M4A, FLAC, AAC, OGG, WMA formats
- **Language Detection**: Automatic detection of spoken language
- **Timestamp Generation**: Creates time-coded transcripts
- **Noise Handling**: Effective transcription even with background noise
- **Speaker Diarization**: Identifies different speakers in conversations
- **Export Formats**: SRT, VTT, or plain text transcript output
- **Long-form Support**: Handles podcasts, interviews, and lectures up to several hours

## Contact and Support

- Email support available
- Comprehensive FAQ sections
- User guides and best practices
- Responsive customer service for translation quality concerns

## Compliance and Security

- HTTPS/SSL encryption for all data transmission
- GDPR-compliant data handling
- Secure payment processing through Stripe
- No unauthorized data sharing or public model training
- User-controlled data retention and deletion

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This website is designed to be helpful for users seeking professional document translation services with AI-powered accuracy and convenience. The platform prioritizes user privacy, translation quality, and ease of use while supporting a wide range of document formats and languages.