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ImgIng / HTML to PDF
CHROMIUM PDF

Preview true HTML pages, minimize losslessly and save the verified PDF

No screenshot flattening, printer workflow or hidden A4 fallback. Five visible stages prepare assets, settle fonts and rendering, run Chromium, minimize the PDF losslessly and write the verified result.

Instant source previewTrue HTML page geometryFive visible stagesAutomatic lossless minimization

Capability quick facts

These facts describe the current product, not unshipped roadmap work.

Layout engine
Same-origin headless Chromium / Skia PDF
Local preview
One HTML file or an explicitly authorized complete local page folder
Submission boundary
Only the frozen script-free snapshot after an explicit Convert action
Result
Verified PDF bytes with automatic generic lossless minimization of repeated vectors and provably invisible font programs

Reviewed by the DataDance product and engineering team · Published · Updated

Finish in three steps

Confirm important settings before export; the processing location is always disclosed.

01

Choose HTML or a page folder

Pick one self-contained file for an immediate preview, or authorize the complete folder when relative CSS, images, fonts, scripts or data are involved.

02

Prepare the true page geometry

Preserve @page size, orientation, margins and pagination; without @page, make the complete rendered webpage one custom PDF page.

03

Generate, minimize losslessly and save

Chromium renders real PDF bytes, then identical vector paths and provably invisible glyph drawing are compacted without resampling images before page, text and link verification.

Why use Chromium rather than flattening the page to an image?

The final appearance of HTML comes from CSS layout, web fonts, SVG, Canvas, page rules, links and browser typesetting. DOM-to-Canvas flattening loses selectable text, vectors and links, while a partial CSS reimplementation cannot cover the web platform. ImgIng therefore uses Chromium’s own printing engine and Skia PDF output to return real PDF bytes.

Why is the page no longer forced into A4?

Follow the HTML’s true page is the default. When @page exists, ImgIng preserves its size, orientation, margins and pagination. A continuous webpage without @page uses its final rendered width and height as one custom PDF page. Fixed-layout HTML exported by ImgIng PDF to HTML carries per-page geometry, so round-tripping restores every source page, including mixed page sizes. A4 and Letter apply only when selected explicitly.

What happens after Convert?

The right panel shows five continuous stages: asset mapping, font and dynamic-rendering readiness, Chromium PDF generation, lossless minimization, and writing to the selected location. The readiness listener is installed before the prepared page loads, so a fast page cannot miss its ready message and wait for a false timeout.

How does generic lossless minimization work?

The optimizer does not recognize one chart library or one SVG layout. It works on PDF content streams generated from ordinary HTML, SVG, Canvas, Chinese and Latin fonts and mixed pages. Mathematically identical filled paths are promoted to shared PDF Form objects while each caller keeps its transform, colour, alpha and clipping state. Visible fonts remain untouched; only Type 3 glyph drawing whose every use is provably invisible is reduced to its original metrics. Images are not resampled or re-encoded in the automatic preset. Page boxes, selectable-text operators and links are re-read afterwards, and any mismatch returns the original Chromium file.

Why can a PDF-to-HTML-to-PDF round trip still be larger?

A fixed-layout HTML export may carry both visible SVG outlines and an invisible selectable-text layer. Chromium must package both layers again. Lossless reuse removes a large amount of repeated drawing, but deleting either layer, rasterizing vectors or replacing fonts would discard information. ImgIng therefore reports the true result rather than forcing it toward the source byte size by degradation.

What remains local and what is submitted?

Choosing files, reading a page folder, instant preview, mapping local CSS, images and fonts, running allowed local scripts in isolation, settling the final view and PDF optimization remain in the browser. On Convert, only the frozen self-contained snapshot is submitted to the narrowly scoped same-origin Chromium process. Remote resources are blocked by default, temporary files are deleted when the request ends, and the renderer cannot resolve external hosts.

Beta limits: exceptionally long one-page documents are proportionally fitted to Chromium’s stable page-size ceiling. Relative imports inside ES modules, Service Workers, extension pages, DRM media, nested iframes and signed-in cross-origin resources cannot be reproduced reliably. The service accepts snapshots up to 64 MB and limits concurrency and render time. Review the centre preview and quality report before conversion.

Updated 2026-08-25 · Live capability detection inside the tool is authoritative

Frequently asked questions

These visible answers match the current product behaviour and structured data.

Are the HTML and local assets uploaded immediately?

No. Import, folder reading, resource mapping and the complete preview stay local. Only clicking Convert submits the frozen script-free snapshot to the same-origin PDF renderer, which deletes temporary files after the request.

Does automatic minimization change images, SVG or fonts?

No. The default preset does not resample images or alter visible fonts. It shares only mathematically identical vector paths and compacts glyph drawing only when every use is provably invisible.

Do I need a printer, PDF re-selection or a separate compression step?

No. Returned PDF bytes are minimized losslessly, re-read for page, text and link semantics, then saved directly. Lossy print, e-book and screen presets remain explicit choices.

Explore ImgIng

Each task page documents real settings, limits and format advice—not keyword-swapped duplicates.