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Lizely

PDF to Long Image

Stack every PDF page into one vertical PNG locally, with adjustable scale and spacing.

Privacy: your files never leave your device. All processing happens locally in your browser.

How to use

  1. 1.Choose one PDF up to 25 MiB and select the rendering scale and gap between pages.
  2. 2.Click Convert to Long PNG; the tool preflights all page and final-canvas dimensions before encoding.
  3. 3.Review the combined width, height, and page count, then download the single long PNG.

About PDF to Long Image

PDF to Long Image renders every page of one PDF and stacks the results from top to bottom in a single PNG. It is designed for a continuous visual strip: sharing a short document in a chat, reviewing slides in one scroll, archiving a multi-page reference as one image, or placing several PDF pages into a page that accepts only one picture. The PDF is processed in your browser and is never uploaded to Lizely.

The output is a page rendering, not a structural PDF conversion. PDF.js paints text, vector artwork, photographs, fonts, clipping paths, and other visible page content onto canvases. The converter then draws those page canvases onto one final canvas. The result does not preserve selectable text, live links, form controls, layers, annotations as editable objects, document metadata, or the original internal images.

Pages can have different dimensions and orientations. The long canvas uses the widest rendered page as its width. Each page is placed horizontally in the center, so narrower portrait pages do not stretch to match a landscape page. A user-selected gap from 0 to 32 pixels separates neighboring pages. The gap area and any side margins are white, and the final image is encoded explicitly as lossless image/png.

Scale changes the raster dimensions before pages are combined. Higher scale can make small content clearer when the long image is viewed at full size, but width, height, memory, and download size increase rapidly. The tool first calculates every page's scaled viewport and the complete combined layout. It does not begin final encoding until this preflight succeeds, preventing a later oversized page from leaving a misleading partial result.

Safety limits keep the operation bounded: the source file may be at most 25 MiB and 40 pages; one rendered page may not exceed 12,000 pixels on either side or 40 megapixels; all page renders together may not exceed 100 megapixels; and the final combined canvas must also remain within 12,000 pixels per side and 100 megapixels. A long document can reach the height limit even when every individual page is small. Reduce scale or use separate PNG files when that happens.

The rendering library and shared PDF worker load only after you press Convert. They are excluded from the initial page path, and the fixed worker URL is shared with the other PDF image converters for browser caching. A newer job cancels an older one. Every per-page canvas is released after it is copied, and the combined canvas and download URL are released when settings change, another file is chosen, or the component unmounts.

The output filename is based on the trimmed input name, removes a final .pdf suffix case-insensitively, replaces desktop-unsafe characters, and ends with -long.png. Encrypted, damaged, unsupported, or over-limit documents show an error. This tool does not bypass passwords, repair PDFs, verify signatures, or assess whether a document is trustworthy.

Use this converter only when one tall image is genuinely the desired format. A very long PNG can be awkward for printers, email clients, image editors, or social platforms. PDF to PNG creates one lossless image per page, while PDF to JPG creates smaller lossy page images. The original PDF remains untouched in every case.

Methodology & sources

Load a bounded PDF only after user action, calculate every scaled page viewport and the complete centered vertical layout before rendering, enforce per-page, aggregate, dimension, and final-canvas limits, render and copy each page onto a white combined canvas, encode one image/png, then release every temporary canvas, task, and object URL.

Frequently asked questions

Does the tool upload my PDF?
No. PDF loading, every page render, stacking, PNG encoding, and download creation run locally.
How are different page widths handled?
The widest page sets the canvas width and narrower pages are centered without stretching.
Why was my document too tall?
The final image has a 12,000-pixel side limit and a 100-megapixel limit; reduce scale or export pages separately.
Can I choose JPG for the long image?
No. This tool deliberately outputs one lossless PNG. Use PDF to JPG for separate JPEG pages.

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