Documents

PDF viewer#

What it does. The most feature-complete document viewer on the site: metadata, forensic document-structure analysis, full text extraction, page-thumbnail previews with a full-page lightbox, embedded raster image extraction, and OCR - all via the vendored pdf.js.

How to reach it. Drop any .pdf. Built in web/assets/js/renderers/pdf.js.

How to use it.

• Info card: application/name/size/page count, Title/Author/Creator/ Producer, creation/modification dates, PDF spec version, page 1 dimensions (points, inches, mm), plus a timestamp-anomaly check (future dates, modified-before-created, vs. the file's own last-modified time).
• Document structure & security card (shown only when something is found): revision count (each save appends a %%EOF marker - more than one means incremental edits are preserved inside the file), linearisation ("fast web view"), trailing data after the final %%EOF (⚠ a polyglot/tamper tell), outline/table of contents (expandable), embedded file attachments, embedded JavaScript with a heuristic risk scan (flags network/file-access/launch/obfuscation/crypto patterns per script, and separately flags auto-run triggers like "Document open" as the riskiest kind), encryption/permissions (allowed vs. restricted actions: print/copy/modify), Keywords/Subject/PDF-A conformance from XMP, and a fonts list (embedded vs. not-embedded, a portability/authenticity tell).
• Text content: extracted per page with reconstructed line breaks; Copy per page; Show next 3 pages/Show all reveal more. If a page has no embedded text (image-only/scanned), a note points at OCR instead.
• Page previews: thumbnails for the first 4 pages (Show next 3 pages/Show all for the rest). Click a thumbnail to open a full-page lightbox with Prev/Next, Zoom (double-click/double-tap, or the toolbar button), and High-res (re-renders the current page at higher resolution for sharper zoom, at a memory/speed cost) - plus a selectable text layer overlaid on the canvas. Per-thumbnail hover actions (always visible on touch): Analyse (renders the page to an image and sends it through the full photo pipeline), OCR (Tesseract on that one page, shown in a popup overlay), PNG (downloads the page as an image).
• Embedded images: click Extract embedded images to pull the original raster images (logos, photos, scans) out of the PDF's content streams - distinct from the rendered page previews. Each found image gets a download link and an Analyse button (up to 300 images).
• OCR - Scan pages as images (collapsible): click Scan all pages to run Tesseract across every page (language picker first), with a progress bar; Show more/Show all reveal more pages of the transcript.

Per-page text controls:

The full-page lightbox toolbar:

Per-thumbnail hover actions, plus the embedded-image and OCR entry points:

Notes / limits. pdf.js is lazy-loaded. OCR and per-page rendering are CPU-heavy for large documents; the UI stages results in batches so nothing blocks on a full-document scan by default.

Shared page-preview presentation (Word/ODF/spreadsheet/presentation text)#

What it does. Formats that have no real page geometry of their own (Word/ODF flowing text, spreadsheets, presentations) get the same "page sheet" experience as PDF: paginateFlow() lays flowing content onto A4-proportioned sheets (breaking to a new sheet when one fills, never splitting a block mid-page), and pagedPreviewCard() builds the thumbnail grid + lightbox reader.

How to reach it. Not used directly - it's the shared rendering substrate for docx.js, odf.js, legacy-office.js, and textdoc.js (callers with genuine natural pages, like one-slide-per-page presentations, build their own page nodes and skip straight to pagedPreviewCard). Built in paged.js.

How to use it. Same controls as PDF's thumbnail/lightbox pattern: Show next N pages/Show all, per-page Copy, and Copy all text.

DjVu scanned documents#

What it does. Decodes and renders DjVu pages (a scanned-document format common for archived books/journals) to canvas, with prev/next paging.

How to reach it. Drop a .djvu/.djv. Built in djvu.js around the vendored pure-JS DjVu.js.

How to use it. ‹ Prev/Next › page through the document; the pager is disabled while a page is rendering (decoding a scanned page can take a moment).

Notes / limits. On memory-constrained (mobile) devices, files over 200MB are rejected with a message to try a desktop browser instead - the whole document is decoded page-by-page in a WASM heap, which can crash a phone tab.

DOCX (Word)#

What it does. Reads Office Open XML Word documents and renders a simplified document view: metadata, formatted text (via the shared page-preview presentation), tables, and text extraction.

How to reach it. Drop a .docx/.docm/.dotx/.dotm. Built in docx.js.

How to use it. Click any embedded inline image to send it through the full photo analyser.

XLSX (Excel, OOXML)#

What it does. Reads Office Open XML spreadsheets and renders each worksheet as a table with sheet tabs and document metadata.

How to reach it. Drop a .xlsx/.xlsm/.xltx/.xltm. Built in xlsx.js.

How to use it. Click a sheet tab to switch worksheets. Each sheet lazily mounts the full tablekit.js table/chart workbench (sort/filter/ search/hide/reorder columns, a chart builder, PNG/JSON/CSV export) - see data-archive.md.

XLSB (Excel Binary Workbook)#

What it does. .xlsb stores a workbook in the binary BIFF12 record format rather than XLSX's XML, so the in-house OOXML reader can't open it - this uses the vendored SheetJS community build purely to decode it into sheets, rendered with the same table UI as .xlsx.

How to reach it. Drop a .xlsb. Built in xlsb.js.

How to use it. Same sheet-tab switching and tablekit.js mounting as XLSX. Metadata additionally flags ⚠ Contains macros (VBA project) when present.

PPTX (PowerPoint)#

What it does. Reads Office Open XML presentations and renders each slide as a card with its title/body text and any embedded images, in presentation order.

How to reach it. Drop a .pptx/.pptm/.ppsx/.ppsm/.potx/.potm. Built in pptx.js.

How to use it. Click a slide thumbnail to open it full-size in a lightbox (× to close); click an embedded image inside a slide to analyse it as a photo.

ODF (OpenDocument: ODT/ODS/ODP)#

What it does. OpenDocument files are ZIP packages whose payload is content.xml (plus meta.xml and a Pictures/ folder). This converts that XML into the same shared page-preview presentation as DOCX/XLSX/PPTX, so ODT reads like the DOCX viewer, ODS like the XLSX viewer, and ODP like the PPTX viewer.

How to reach it. Drop a .odt/.ott/.fodt/.sxw (text), .ods/ .ots/.fods/.sxc (spreadsheet), .odp/.otp/.fodp/.sxi (presentation), or .odg/.otg/.fodg/.sxd (graphics). Built in odf.js.

How to use it. Text documents get paged.js's pagination controls; spreadsheets mount the tablekit.js workbench.

Legacy binary Office (DOC/XLS/PPT, 97-2003)#

What it does. The pre-2007 Office formats are OLE2/Compound File containers, not ZIP+XML - there's no clean styled layout to recover the way DOCX/ODT give, so this is deliberately best-effort: it pulls the readable content out and shows it through the same page-sheet preview as the other document viewers. .doc reads Word text via the FIB piece table (CLX/PlcPcd), paginated as pages.

How to reach it. Drop a .doc, .xls, or .ppt. Built in legacy-office.js.

How to use it. Same pagination controls as the other paged-document viewers; a plain hyperlink list surfaces embedded/external links the legacy document referenced.

Text and lightweight-markup documents#

What it does. A family of formats whose content is really just text or simple XML/HTML, each shown as readable prose or selectable source: markup source (DITA, TEI, JATS, reStructuredText, AsciiDoc, Org, Textile, TeX/LaTeX, BibTeX), RTF (control words stripped to readable prose), AbiWord (.abw, XML), FictionBook (.fb2, XML e-book), HWPX, MHTML.

How to reach it. Drop any of the above extensions. Built in textdoc.js, reusing paged.js's pagination controls (Show next N pages/ Show all, Copy all text, per-page Copy).

Apple iWork (Pages / Numbers / Keynote)#

What it does. Modern iWork files (2013+) store content as Snappy-compressed, undocumented Protocol Buffer streams in Index/*.iwa - there's no practical way to re-render that in the browser. Instead, Analyser shows the QuickLook preview Apple bakes into the package: an embedded Preview.pdf (rendered page-by-page via the PDF viewer) or, failing that, the largest preview/thumbnail image. Files saved without a preview fall back to a metadata-only readout.

How to reach it. Drop a .pages/.numbers/.key/.keynote. Built in iwork.js.

How to use it. If a Preview.pdf exists, it's shown via the full PDF viewer (inheriting all its controls). Otherwise, if a thumbnail image exists, click Analyse this image to send it through the photo pipeline.

Notes / limits. .key collides with PEM cryptographic key files (not a ZIP); if the dropped .key isn't actually a ZIP package, it's handed to proprietary.js's identifier instead so a real private key still gets read. Format detected as "iWork 2013+ (IWA)" vs. "iWork '09 (XML)" based on package contents.

EPUB reader#

What it does. Reads zipped XHTML e-books: metadata, cover, and chapter-by-chapter reading with navigation.

How to reach it. Drop a .epub. Built in epub.js.

How to use it. ← Prev/Next → page through chapters; the chapter select dropdown jumps directly to any chapter.

Kindle / Mobipocket e-books (MOBI/AZW/AZW3)#

What it does. Decodes MOBI 6 and KF8 (AZW3, and combo .mobi) e-books fully in the browser via the vendored foliate-js: metadata and cover, then a section-by-section reader with each section decoded to a self-contained HTML blob shown in a sandboxed (scriptless) iframe with images resolved.

How to reach it. Drop a .mobi/.azw/.azw3. Built in mobi.js.

How to use it. ‹ Prev/Next › step through sections; the pager is disabled while a section loads (KF8's HUFF/CDIC decompression can be slow).

Microsoft Access databases (MDB/ACCDB)#

What it does. Opens a Jet/ACE database fully in the browser via the vendored mdb-reader: lists user tables with their columns and row counts, and shows a sample of rows from each - the same table UI as the spreadsheet viewers.

How to reach it. Drop a .mdb/.accdb. Built in mdb.js.

How to use it. Click a table tab to switch tables; rows are capped at 200 shown per table (a note states the true count when truncated).

Jupyter notebooks#

What it does. Renders an .ipynb the way a reader sees it: narrative markdown cells, code cells with their In[n] prompt, and captured outputs (stream text, execute results, rich display data including PNG/JPEG images decoded from base64 data URIs, and errors).

How to reach it. Drop a .ipynb. Built in notebook.js.

How to use it. Show more cells/Show all reveal more of a long notebook.

Markdown#

What it does. Renders .md/.markdown as formatted HTML alongside document stats and the raw source, using a self-contained CommonMark-ish + GitHub-Flavoured-Markdown parser (no dependency): headings (ATX + setext), bold/italic/strikethrough, inline and fenced code, links, images, blockquotes, nested ordered/unordered lists, task lists, GFM tables, and horizontal rules.

How to reach it. Drop a .md/.markdown file. Built in markdown.js.

Notes / limits. All text is HTML-escaped and raw inline HTML is rendered as literal text - the renderer never executes embedded HTML/script content, for safety when previewing an untrusted Markdown file.