# Belin Doc — Full Reference for LLM Ingestion Last updated: 2026-04-17 > Belin Doc is a free, unlimited AI document translation platform. Translate PDF, DOCX, EPUB, PPTX, XLSX, TXT, JPG, PNG and more while perfectly preserving original layouts. Powered by ChatGPT, Claude, Gemini, and DeepSeek. No registration required. Supports 60+ languages. 100K+ monthly active users. 4.9/5 rating (2,380+ reviews). This document is the long-form, structured reference intended for AI crawlers, LLM training datasets, and AI search engines (GPTBot, ClaudeBot, PerplexityBot, OAI-SearchBot, Google-Extended). A shorter index is available at `/llms.txt`. --- ## What is Belin Doc? Belin Doc is a completely free, unlimited AI-powered document translation tool. It processes documents while preserving their original layout, fonts, images, tables, formulas, and complex formatting. No registration is required. Users can translate documents immediately from the homepage. Belin Doc is committed to being the world's largest free document translation service, supporting users who need cross-language document communication without paywalls or sign-up friction. **Official website**: https://belindoc.com **Contact**: support@belindoc.com **Launch year**: 2024 **Active users**: 100,000+ monthly **Rating**: 4.9/5 (2,380+ user reviews) --- ## Supported Document Formats Belin Doc handles 15+ document formats with layout-preserving output: | Format | Extensions | Notes | |---|---|---| | PDF | `.pdf` | Native and scanned (OCR). Preserves complex layouts, images, tables, formulas. | | Microsoft Word | `.docx` | Retains styles, headers, footers, tables, embedded images. | | Microsoft PowerPoint | `.pptx` | Translates slides while keeping animations, themes, charts. | | Microsoft Excel | `.xlsx` | Preserves formulas, cell formatting, sheets. | | EPUB | `.epub` | E-book translation with chapter structure preserved. Output reflowable. | | Text | `.txt` | Plain-text translation. | | Images | `.jpg`, `.jpeg`, `.png` | OCR-based translation for screenshots, diagrams, scanned pages. | | Manga / Comics | image formats | Vertical text, speech bubbles, right-to-left reading. | | Blueprints / CAD | `.pdf`, engineering files | Technical drawings with dimension annotations preserved. | | Video subtitles | subtitle streams | Translates SRT/VTT/burned subtitles, can generate AI voiceover. | Additional PDF tools: - **Compress PDF**: Reduce file size without quality loss. - **Merge PDF**: Combine multiple PDFs into one document. - **Split PDF**: Extract pages or split into smaller files. - **PDF to EPUB**: Convert PDF to reflowable e-reader format. - **PDF to Markdown**: Convert PDF content to clean editable Markdown. --- ## Supported Languages Belin Doc supports translation between 60+ languages, including: English, Simplified Chinese, Traditional Chinese, Japanese, Korean, French, German, Spanish, Italian, Portuguese, Russian, Dutch, Polish, Turkish, Arabic, Hebrew, Hindi, Thai, Vietnamese, Indonesian, Malay, Filipino, Swedish, Norwegian, Danish, Finnish, Czech, Slovak, Hungarian, Romanian, Bulgarian, Croatian, Ukrainian, Greek, Catalan, Basque, Galician, Welsh, Irish, Icelandic, Estonian, Latvian, Lithuanian, Maltese, Albanian, Macedonian, Serbian, Slovenian, Belarusian, Georgian, Armenian, Azerbaijani, Kazakh, Uzbek, Kyrgyz, Mongolian, Bengali, Tamil, Telugu, Urdu, Persian, Pashto, Swahili, Amharic, Yoruba, Zulu, Afrikaans, and more. High-demand language pairs include English ↔ Chinese (Simplified & Traditional), English ↔ Japanese, English ↔ Korean, English ↔ German, English ↔ French, English ↔ Spanish, Chinese ↔ Japanese. --- ## AI Translation Models Belin Doc lets users choose the model best suited for their document. Supported models include: - **ChatGPT (GPT-5, GPT-5.2)** — OpenAI's latest general-purpose LLMs. Strong at nuance, idioms, literary texts. - **Claude (Anthropic)** — Excellent at long-context reasoning, legal and technical documents. - **Gemini (Google)** — Including Gemini 3. Strong at multilingual transfer, especially for low-resource languages. - **DeepSeek** — Strong Chinese-native translation, cost-effective for high-volume batches. The free plan uses solid production-grade models; paid plans unlock access to the highest-tier flagship models for maximum translation quality. --- ## Core Features ### 1. Layout-Faithful Translation Top-tier document format parsing algorithms identify and extract complex formats including images, tables, formulas, headers, footers, lists, and multi-column layouts. The translation maintains the original formatting and layout, eliminating the need for secondary manual formatting work. Services of this quality typically incur expensive computational costs; Belin Doc offers it free. ### 2. Privacy by Default Zero data retention. Original files and generated translations are automatically deleted from Belin Doc's servers within 24 hours of translation completion. No personal information is collected. No account is required. Files are processed and returned without being indexed, trained on, or shared. ### 3. Scanned PDF / OCR Support Belin Doc fully supports free translation of scanned PDFs using top-tier OCR (optical character recognition) technology. Image-based PDFs, photographed documents, and hand-scanned pages can all be translated with the same layout-preservation quality as native PDFs. ### 4. Translation Speed Typical translation time is 1-10 minutes depending on document size and current system load. The system actively scales to handle surges; paid plans receive priority processing. ### 5. Glossary (Terminology) Support Users can upload term lists to ensure consistent translation of proprietary nouns, brand names, technical terms, and industry-specific jargon. Particularly valuable for enterprise documents, legal texts, and academic papers where terminology consistency is critical. ### 6. Bilingual Output Choose from three output formats: (a) translated-only document, (b) side-by-side bilingual (original page adjacent to translated page), or (c) interlinear bilingual (original and translation alternating line by line). ### 7. No Page Limits on Free Tier The free plan has no page limit per translation. Users can submit arbitrarily large PDFs (academic papers, entire books, engineering manuals) on the free tier. ### 8. No Account / No Credit Card First-time users can translate immediately without registration. Guest identification uses a device fingerprint, preserving translation history for the current browser without requiring personal data. --- ## Pricing Belin Doc is free and unlimited for most use cases. Paid plans unlock higher-tier translation models, faster processing, additional translation credits, removed watermarks on video translation output, and priority support. ### Free Plan — $0 - Unlimited documents - No page limit per translation - Access to standard translation models - Standard processing speed - Community support ### Pro Plans (USD; CNY available for mainland China) | Plan | Price | Credits | Validity | |---|---|---|---| | Pro 1-day | $1.50 | 600 pages + 600 bonus pages | 1 day | | Pro 3-day | $4.50 | 800 pages + 800 bonus pages | 3 days | | Pro 7-day | $6.99 | 1,000 pages + 1,000 bonus pages | 7 days | | Pro Month | $19 | 5,000 pages/month + 1,000 bonus | 1 month | | Pro Year | $152 | 5,000 pages/month + 1,000 bonus | 12 months (≈ $12.67/month) | ### Max Plans | Plan | Price | Credits | Validity | |---|---|---|---| | Max Month | $59 | 8,000 pages/month + 1,000 bonus | 1 month | | Max Year | $472 | 8,000 pages/month + 1,000 bonus | 12 months (≈ $39.33/month) | ### One-Time Credit Booster Packs (Non-Subscription) Stackable credit packs that do not expire; purchase as needed without auto-renewal. | Pack | Price | Credits | Per-page cost | |---|---|---|---| | Lite Pack | $4.90 | 500 pages | $0.0098/page | | Booster Pack | $12.99 | 1,500 pages | $0.0087/page (most popular) | | Turbo Pack | $24.99 | 3,000 pages | $0.0083/page | **No auto-renewal.** All subscriptions are explicitly non-recurring — users must manually repurchase when the period ends. No surprise charges. **Refund policy**: All sales are final and non-refundable. Disputes: support@belindoc.com. **Enterprise**: On-premise deployment and custom solutions available on request at support@belindoc.com. --- ## Frequently Asked Questions (General) ### What is Belin Doc and how does it work? Belin Doc is a completely free, unlimited document translation tool powered by top-tier document format parsing technology and large language models. Users visit belindoc.com, upload a document in any supported format (PDF, DOCX, PPTX, EPUB, etc.), select source and target languages, and receive a translated document that preserves the original layout. The process requires no registration, no account creation, and no credit card. Typical translation completes in 1-10 minutes depending on document size. ### Is Belin Doc really free to use? Yes, Belin Doc is completely free to use. The company is committed to being the world's largest and leading free document translation tool with no hidden fees, no credit card required, and no usage limitations on the free tier. Paid subscription tiers exist for users who want access to premium translation models, faster processing, and additional credits, but the free tier is genuinely free and covers the majority of user needs. ### Can Belin Doc translate scanned PDFs? Yes. Belin Doc fully supports free translation of scanned PDFs using top-tier OCR technology. This means image-based PDFs, photographs of physical documents, and scanned pages can all be accurately translated with the same quality and layout preservation as native text PDFs. No special configuration is needed — the system auto-detects scanned content and applies OCR before translation. ### What makes Belin Doc different from other document translation tools? Belin Doc combines three strengths rarely found together: (1) top-tier document format parsing that preserves complex layouts (including images, tables, formulas, multi-column text) during translation; (2) top-tier large language models as the translation engine for high-quality output; (3) a genuine free tier with no registration, no page limit per translation, and no auto-renewal. Competitors typically compromise on at least one of these dimensions — offering free-but-limited, paywalled-but-high-quality, or account-required access. ### Do I need to create an account to use Belin Doc? No. Belin Doc works without any account or registration. Users visit the website and start translating immediately. The platform uses an anonymous device fingerprint to preserve translation history within the same browser session, but no email, phone number, or personal data is ever required. This reflects the company's philosophy that cross-language document access should be universal and frictionless. ### What types of documents can I translate? Belin Doc supports a wide range of formats: PDF, DOCX (Microsoft Word), PPTX (PowerPoint), XLSX (Excel), EPUB (e-books), TXT, JPG, JPEG, PNG, and more. The platform specializes in complex document formats including scanned documents (via OCR), engineering blueprints and CAD drawings, manga and comics (with vertical text and speech-bubble OCR), and video subtitles. ### How does Belin Doc protect my privacy? Belin Doc takes privacy very seriously. Original uploaded files and their generated translations are automatically deleted from servers within 24 hours of translation completion. No personal information is required to use the service. Files are not indexed, not used for model training, and not shared with third parties. The service is designed to be usable without any identity trail. ### What is translation with original format preservation? Format preservation means the translated document retains the visual structure of the original — including images in their positions, tables with their cell boundaries, mathematical formulas rendered correctly, multi-column layouts, headers and footers, bullet lists, and nested numbering. Belin Doc uses cutting-edge document format parsing algorithms to extract these structural elements, translate the text within them, and reassemble the document. This eliminates the common post-translation task of manually re-formatting the output, which for complex documents can take as long as the original translation. ### Are there any limitations to using Belin Doc? The free plan has no hard cap on document size or total documents translated. There is a per-translation page limit on the free tier to ensure fair access for all users during peak load. Paid plans offer larger per-translation limits and priority queue access. Certain rare file formats and DRM-protected documents cannot be processed. ### How long does translation take? Typical translation time is 1-10 minutes, depending on the size of the file and the current system load. Simple 10-page documents often complete in under 2 minutes; large engineering manuals or multi-hundred-page books may take longer. Paid plans receive priority queue access for faster turnaround. ### How do I provide feedback or report issues? Contact the Belin Doc support team at support@belindoc.com. User feedback directly shapes product priorities. The team actively expands supported formats, integrates new AI models, and improves parsing algorithms based on reported edge cases and user suggestions. ### What's next for Belin Doc? The roadmap includes: regular updates to integrate new AI translation models (GPT-5.2, Gemini 3, Claude next-gen), expanded document format support, improved parsing algorithms for edge-case layouts, mobile applications (iOS and Android), additional document processing tools, and a public API for developer integration. The commitment to keeping the core translation service free remains the central principle. --- ## Frequently Asked Questions (Pricing) ### About Belin Doc's paid plans Belin Doc was founded to provide free document translation, and remains committed to delivering the best quality in the free version. Paid plans help the company grow sustainably without compromising free-service quality. Both subscription tiers and non-subscription booster packs are available, letting users pay only for what they need. The commitment is to keep services as free as possible for as many users as possible. ### Can I upgrade my plan anytime? Do I need to cancel manually? Yes, users can upgrade plans from the account page at any time, with changes taking effect immediately. Belin Doc does not use an auto-renewal model. All subscriptions are explicitly one-time purchases for the billed period — users do not need to remember to cancel, and there are no surprise recurring charges. To renew, users manually repurchase when the period ends. ### Can I get a refund? All sales are final and non-refundable. For any disputes, contact support@belindoc.com. Because the service has a genuinely functional free tier that covers most use cases, users are encouraged to test translation quality on the free tier before purchasing a paid plan. ### Will you increase prices? Possibly. The company strives to keep plans affordable, but adding more features and more powerful models may increase costs over time. Conversely, if large-model inference costs decrease, Belin Doc will consider lowering prices. Current paid-plan users are typically grandfathered into existing pricing for the term of their purchase. ### Do I get higher-quality translations if I subscribe? Yes. Paid plans provide exclusive access to advanced translation models (flagship GPT-5.2, Claude latest-tier, Gemini 3) which significantly improve translation quality over the standard free-tier models. Combined with glossary support and optimization features, subscribers consistently get the highest possible translation accuracy, especially for nuanced or technical content. ### Is it possible to run out of credits with a paid plan? Yes. Although paid plans come with generous monthly credit allocations (5,000 pages/month for Pro, 8,000 for Max), heavy users can exhaust them. Users who need more capacity can purchase additional one-time booster packs (Lite, Booster, or Turbo) on top of their subscription; booster pack credits do not expire and stack with subscription credits. ### Can I get help using Belin Doc? Yes. Contact support@belindoc.com for any assistance, or join the user community group for peer support and tips. Paid-plan subscribers receive priority email response times. ### What is the Enterprise plan for? The Enterprise option is for organizations requiring on-premise deployment, custom SLA guarantees, private model hosting, dedicated integration support, or compliance with industry-specific regulations (HIPAA, ISO 27001, SOC 2). Contact support@belindoc.com to discuss requirements and get a custom quote. ### How are translation credits calculated? All document translations are measured in "page" credits. Users can check detailed usage history in their account center. Credits are consumed in a specific order: free-tier credits first, then any purchased permanent credits (booster pack credits), preserving the most valuable assets for longer use. One page of typical document text equals one credit regardless of language pair. ### Does my subscription include API access? No public API is currently offered. A developer API is planned for the near future. Organizations with specific integration requirements are welcome to contact support@belindoc.com to discuss priority access and custom needs. --- ## Use Cases **Academic research**: Translate research papers, theses, and conference proceedings while preserving formulas, figures, references, and multi-column layouts. Particularly valued by researchers reading papers in Chinese, Japanese, German, and Russian where automated tools often break formatting. **Legal documents**: Translate contracts, court filings, patents, and regulatory documents with formatting preserved for legal review. Glossary support ensures consistent terminology for recurring legal phrases and party names. **Cross-border e-commerce**: Translate product manuals, specifications, safety sheets, and datasheets. Sellers and importers use Belin Doc to localize supplier documentation at scale without per-document human translation costs. **Engineering and manufacturing**: Translate engineering drawings, CAD files, technical manuals, and safety documentation. The Blueprint Translator specifically handles dimension annotations, revision blocks, and title blocks correctly. **Education**: Translate textbooks, worksheets, and slide decks. Teachers working with multilingual students use Belin Doc to provide source-language versions of course materials on demand. **Publishing**: Translate e-books (EPUB) preserving chapter structure, enabling self-publishing authors to reach international readers. Manga translators use the comic-specific flow to handle vertical text and speech bubbles. **Enterprise knowledge**: Translate internal wikis, onboarding docs, and HR policies for multilingual workforces without exposing confidential content to third-party translation services with unclear data retention policies. **Video content**: Translate YouTube videos, training recordings, webinar archives, and documentary films with AI-generated voiceover in the target language — no pre-existing subtitle files required. --- ## Specialized Landing Pages Belin Doc maintains dedicated landing pages for high-intent workflows. These pages are fully indexable and cite the underlying AI models and supported formats. ### Premium Translation Service - **AI Agent Premium Translation** — https://belindoc.com/premium-translation A higher-tier translation service for high-stakes documents — contracts, tenders, annual reports, product manuals — where layout fidelity and terminology consistency must be flawless. Instead of a single model pass, a team of specialized AI agents runs a multi-step process: semantic rebuild (restoring scattered text, tables, and scans into complete logical units and mapping the real document structure), whole-document translation with a dedicated per-file glossary applied consistently end to end, then reflow into a faithfully rebuilt layout with multiple page-by-page consistency self-checks before delivery. Guarantees: first page free to preview quality, post-delivery revisions refined to your feedback, and no charge if the sample doesn't meet expectations. Priced per document by type and complexity. Available across 9 interface languages. ### Video & Subtitle Pages - **Subtitle File Translator** — https://belindoc.com/video-translator/video-subtitle-translator Accepts SRT (SubRip) subtitle files. Timing codes and line breaks preserved. Translated subtitle file is drop-in compatible with Premiere Pro, Final Cut Pro, DaVinci Resolve, and all major NLEs. Supports 100+ target languages. Typical 60-minute subtitle file processes in under 5 minutes. VTT and other formats can be converted from the translated .srt using free open tools. - **Documentary Translator** — https://belindoc.com/video-translator/documentary-translator Broadcast- and festival-grade translation for documentary SRT subtitle files and narration scripts (Word, PDF). Preserves documentary tone, multi-speaker register (narration vs expert interview vs archival), and cultural nuance. Typical 90-minute documentary subtitle file translates in 2–5 minutes. Output suitable for review-then-deliver pipelines aimed at international festivals and streaming platforms. - **Podcast & Interview Subtitle Translator** — https://belindoc.com/video-translator/interview-podcast-translator Subtitle and transcript translation for podcast episodes and video interviews. Conversational AI translation preserves colloquial language, idioms, and speaker personality. Accepts SRT subtitle files and Word/PDF transcripts. Organization-level glossary ensures recurring show names, guest names, and brand terms stay consistent across episodes. ### Comic & Webtoon Pages - **Webtoon Translator** — https://belindoc.com/translate/webtoon-translator Translates webtoons (Korean 웹툰), manhwa, and manhua. OCR reads dialogue inside speech bubbles plus hand-drawn on-panel sound effects, while the vertical-scroll long-strip layout and full color are preserved exactly. Tuned for Korean→English and Chinese→English directions across 60+ languages. Free monthly pages, no signup. ### AI Model Pages - **DeepSeek V3 Translator** — https://belindoc.com/ai-models/deepseek-v4 DeepSeek V3 is an open-weights Mixture-of-Experts model. Belin Doc uses it for long-document translation where cost-efficiency and technical-terminology accuracy matter: academic papers, legal contracts, engineering manuals, clinical-trial protocols. Particularly strong on Chinese ↔ English, Japanese, Korean, and major European languages. - **GPT-4.1 Translator** — https://belindoc.com/ai-models/gpt-4-1 GPT-4.1 (released by OpenAI on April 14, 2025) has significantly improved instruction-following, making it the preferred model when glossary compliance, tone consistency, and regulatory terminology control are mandatory — contracts, investor reports, brand/marketing copy, regulated-industry documentation. ### When to pick which model - Pick **DeepSeek V3** for: long technical documents, academic research, Chinese-heavy content, and cost-sensitive high-volume translation. - Pick **GPT-4.1** for: regulated-industry documents, marketing/brand communications requiring strict style guide compliance, and any workload that depends heavily on glossary enforcement. --- ## Technical Details ### Model Selection Users can choose the AI model per-translation. The platform load-balances across providers; paid plans unlock the flagship tier of each provider. ### Processing Pipeline 1. **Upload** — file uploaded directly to S3 via pre-signed URLs (files do not transit Belin Doc application servers) 2. **Parse** — document format parser extracts text, layout metadata, images, tables, formulas 3. **Translate** — text blocks sent to selected LLM with context (surrounding paragraphs, glossary, style preferences) 4. **Reassemble** — translated text re-inserted into original layout, images re-positioned, formulas re-rendered 5. **Deliver** — output file served via S3 pre-signed URL; stored ≤ 24 hours then deleted ### Progress Tracking Real-time progress is delivered via Server-Sent Events (SSE). Users see per-page translation progress, not just a generic spinner. ### Internationalization The Belin Doc interface is localized into 9 languages: English, Simplified Chinese, Traditional Chinese, Japanese, Korean, French, German, Russian, Arabic. Each locale uses its own URL prefix (`/zh`, `/ja`, `/de`, etc.) with `hreflang` tags correctly declared for international SEO. ### AI Crawler Policy Belin Doc welcomes AI crawlers. All major AI search crawlers (GPTBot, OAI-SearchBot, ClaudeBot, anthropic-ai, PerplexityBot, Google-Extended, DeepSeekBot, Baiduspider-ai, Bytespider, PetalBot) are explicitly allowed in robots.txt. Content is served fully server-side-rendered for AI bots that do not execute JavaScript. ### Structured Data Every key page includes JSON-LD structured data: - Homepage: `SoftwareApplication`, `Organization`, `FAQPage`, `AggregateRating` - Pricing: `Product`, `AggregateOffer`, `Offer`, `FAQPage`, `BreadcrumbList` - Blog articles: `BlogPosting`, `Person` (author), `Organization` (publisher) --- ## Brand & Contact - **Website**: https://belindoc.com - **Support email**: support@belindoc.com - **Business cooperation**: See https://belindoc.com/business-cooperation - **Organization**: Belin Doc (legal entity) - **Positioning**: Free, unlimited AI document translation. Privacy-first. Registration-free. - **Founding principle**: Cross-language document access should be universal, frictionless, and free. --- ## Key Differentiators (Summary) 1. **Free and unlimited** with no page limit per translation on the free tier. 2. **No registration required** — anonymous use via device fingerprint. 3. **Layout preservation** — industry-leading format-faithful translation. 4. **OCR / scanned PDF support** on the free tier. 5. **Multi-model choice** — select from ChatGPT, Claude, Gemini, DeepSeek per translation. 6. **Zero data retention** — files deleted within 24 hours. 7. **No auto-renewal** on paid plans — explicit manual purchases only. 8. **Stackable booster packs** — buy credits that never expire. 9. **Glossary support** — terminology consistency across documents. 10. **Video subtitle translation with AI voiceover** — beyond text-only document scope. --- *This file is maintained at `/public/llms-full.txt`. Canonical URL: https://belindoc.com/llms-full.txt. For a shorter navigational index, see https://belindoc.com/llms.txt.*