🔬Alpha Preview — Multi-page scanned, image, and text-layer PDF. 10 output languages. 7 themes.

ALPHA

ScanExplain

Translate & explain scanned, image, and text-layer PDFs — multi-page, 10 languages, 7 themes. In-browser OCR + AI-powered insight. Free Chrome extension.

Add to ChromeChrome first launch

Chrome Web Store listing is being finalized.

See what it does ↓

🧪 Alpha Preview — Multi-page scanned/image/text-layer PDF. 10 output languages. 7 popover themes. Expect rough edges & rapid iteration.

Why ScanExplain Exists

Every major translation tool rejects scanned and image-based PDFs. We built ScanExplain to fill this gap.

Tool	Product	Scanned PDF Support
Immersive Translate	BabelDOC	✗ Does not support scanned, image-based, or OCR-based PDFs
Immersive Translate	PDF Pro	✗ Not suitable for scanned PDFs and academic papers
Google Translate	Document Translation	✗ Scanned PDFs return empty or garbled text
DeepL	Document Translator	✗ Requires selectable text — image PDFs silently fail
ScanExplain	Chrome Extension	✓ In-browser OCR + AI translation & explanation

What's Inside

The features that make ScanExplain more than a one-page OCR toy.

Multi-page Reading

Header pagination. Background batch-OCR for every page. Per-page result cache — re-open in seconds.

Pin & Collapse Bubble

Pin explanations to keep them visible. Collapse to a chip while you keep reading. Re-expand on click.

6 Annotation Tools

Marker, wave, straight line, strike-through, write a thought, or open an AI discussion on any block.

10 Output Languages

English, Simplified/Traditional Chinese, Japanese, Korean, German, Italian, Portuguese, Spanish, French. Follows system locale.

Auto Native-vs-OCR

Text-layer PDFs skip the ONNX model and read the embedded text directly. Force-OCR available per page.

Settings · Providers · Tasks · Dry-Run

Full Provider & Prompt Task SCRUD. Dry-run tasks against your providers before saving.

7 Popover Themes

Basic, Pro, Creative, Galaxy, Neon, Cyberpunk, Aurora. Switch from the popover header.

Select & Explain on Any Webpage

Content script mounts on http/https sites. Select any text → popover with lexical / etymology / info.

Built For

Three real use cases where ScanExplain pays for itself.

Academic Papers & Textbooks

Read scanned or foreign-language papers cover-to-cover. Multi-page batch OCR, in-header pagination, in-line explanation of jargon.

Example

A 30-page French economics PDF → translated to English, per-page explanation, cached for offline re-read.

Contracts & Scanned Documents

Image-based contracts, invoices, IDs. OCR the text, then summarize and explain clauses in your language.

Example

Scanned vendor agreement in German → summary + risk-flag annotations + per-clause translation.

Foreign-Language Web Reading

On any http/https page, select a word → bubble with translation, etymology, and contextual info.

Example

Reading a Spanish tech blog → select a phrase → lexical breakdown + etymology in seconds.

What It Does

8 features available now. 1 more in active development.

In-browser OCR

Runs entirely in your browser. No server upload, no data leaves your device.

✓ Available

AI Translation

Recognized text is translated to your configured language (10 options) using a remote LLM. OCR is fully on-device.

✓ Available

AI Explanation

Not just translation — get lexical breakdowns, etymology, and contextual insights on any text block.

✓ Available

Select & Explain (Web)

Select any text on any webpage and get an AI-powered explanation popover. Works on all sites.

✓ Available

7 Theme Variants

Basic, Pro, Creative, Galaxy, Neon, Cyberpunk, Aurora — pick the popover style you like.

✓ Available

Multi-page Processing

Full document, batch OCR + page-cached, page navigation in header.

✓ Available

Multi-language Output

10 output languages: English, Simplified/Traditional Chinese, Japanese, Korean, German, Italian, Portuguese, Spanish, French.

✓ Available

Annotation Tools

Marker, wave, straight line, strike-through, write a thought, or open AI discussion on any text block.

✓ Available

Save & Library

Bookmark explanations and build a personal knowledge library.

Coming Soon

Document Support

Built for scanned & image PDFs that other tools reject. More formats on the way.

Scanned PDF

Paper documents digitized by scanner

Full document, per-page OCR cache

✓ Supported

Image-based PDF

PDFs containing embedded images instead of text layers

Full document, per-page OCR cache

✓ Supported

Regular PDF (text-based)

Standard PDFs with selectable text

Auto-detected; force OCR available

✓ Supported

Multi-page PDF

Full document processing beyond page one

Full document, per-page OCR cache

✓ Supported

Image files (PNG / JPG)

Standalone image uploads for OCR

Single image

✓ Supported

EPUB / DOCX

Browser Support

Chrome first. Other Chromium-based and cross-platform browsers on the roadmap.

Chrome

Alpha available now

●✓ Available

Edge

Planned — shared Chromium engine

○Coming Soon

Firefox

Planned

○Coming Soon

Safari

Planned

○Coming Soon

⚠️ Known Alpha Limitations

•Translation uses a remote LLM — the recognized text is sent to your configured provider (zhipu / siliconflow). OCR stays fully on-device.
•In-browser OCR works best with printed text. Handwriting recognition is not supported.
•Very large files (>50 MB) may cause slower processing due to browser memory limits.
•The popup UI and PDF Reader page are functional shells — full integration is in progress.