How to convert PDF to PNG on iPhone
If the PDF page contains text, tables, charts or line art — which is most PDFs — PNG is the better rendering target than JPG. It is lossless, so the letter edges stay clean instead of picking up compression fuzz.
The first page only. A PNG holds one image; a PDF can hold hundreds of pages. Convexy renders page 1. To convert any other page, first use the free PDF Split tool (under Tools) to extract that page into its own PDF, then convert that file. Stated up front so nothing is a surprise later.
Why PNG beats JPG for documents
JPEG compression works by discarding high-frequency detail — and a sharp black letter on a white background is nothing but high-frequency detail. That is why text rendered to JPG picks up faint halos and speckling around every glyph, an artefact known as ringing or mosquito noise. Zoom in on a JPG of a text page and you will see it immediately.
PNG is lossless. It stores every rendered pixel exactly, so a black pixel stays black and the edge of a letter stays a clean edge. For a page of text, a table, a chart, an invoice, a legal document, or engineering line art, PNG is the correct choice. The file will be larger than the equivalent JPG, and it will look right.
The exception: if the page is mostly a large photograph, JPG will be far smaller with no visible penalty.
Choosing the resolution — this is the real decision
A PDF page is drawing instructions, not pixels. It has no native resolution: it can be printed on a billboard and stay sharp. Converting to PNG rasterises it — freezes it onto a fixed pixel grid — and you choose how fine that grid is. In Options, the PDF quality setting maps to actual dpi:
- Screen — 72 dpi. The page's native point size. Fine for a thumbnail; small print will not be legible.
- Standard — 150 dpi. Double the linear resolution. The sensible default for on-screen reading.
- High — 300 dpi. Print quality. Text stays crisp when zoomed or printed. Files get big — a 300 dpi lossless render of an A4 page is a lot of pixels — but this is the setting for anything that matters.
Rasterisation is one-way. Enlarging a 72 dpi PNG afterwards does not recover detail that was never drawn; it just interpolates blur. If in doubt, render high.
Pages are rendered onto a white background. Unpainted or transparent regions of the PDF come out white rather than transparent. For a document that is invariably what you want. PNG can hold an alpha channel, but the rendered page will not have transparent areas to put in it.
If you want the words, don't do this at all
Rendering to PNG converts text into a picture of text. The characters cease to exist as characters — nothing can search, select or copy them, and no automated system can read them without OCR.
If what you actually want is the content, convert the PDF to TXT instead. Convexy extracts the real text layer from the document, giving you actual characters. That is a different operation entirely, and it is the right one far more often than people realise. Convert to PNG when you want an image of the page: a figure for a slide, a preview, a diagram to annotate, something to post.
No server, no upload
PDFs are typically the most private documents anyone owns — contracts, payslips, tax filings, medical results, legal letters. Handing one to a free online converter, which must upload it to a machine you know nothing about, is a poor bargain for a PNG.
Convexy renders with Apple's PDFKit on the device itself. No backend, no account, no network call. It works in Airplane Mode, which is the simplest possible way to check that claim yourself.
How to do it
-
Split out the page you need (unless it's page 1)
Open Tools, choose PDF Split, and extract the page into its own PDF. Free tool, no purchase required. Skip if you want the first page.
-
Bring the PDF in
Tap Browse files and pick the PDF, or share it into Convexy from Mail, Files or wherever it lives.
-
Choose PNG
A PDF can become JPG, PNG, TIFF or TXT. Tap PNG for text and line art. If it is the actual text you want, choose TXT instead.
-
Pick the dpi
In Options set the PDF quality: Screen (72 dpi), Standard (150 dpi) or High (300 dpi). Choose High for anything with small text or destined for print — you cannot add resolution afterwards.
-
Convert, then save or share
The page is rendered losslessly onto a white background. Save it to Photos or Files, rename it, or send it straight on.
Common questions
Is PNG or JPG better for converting a PDF?
PNG, for almost any document. It is lossless, so text and line edges stay sharp. JPEG compression specifically damages high-contrast edges — the exact thing letters are made of — leaving visible halos around glyphs. Choose JPG only when the page is dominated by a photograph, or when file size is the binding constraint.
How do I convert all the pages of a PDF to PNG?
Convexy renders the first page. For other pages, use the free PDF Split tool to extract them into individual PDFs, then convert those — you can select several at once and run them as a batch. It is an extra step compared to tools that promise one-click multi-page export, but you always know exactly which page you got.
What dpi should I use?
150 dpi (Standard) for screen viewing, 300 dpi (High) for printing or for pages with small text you need to keep legible. 72 dpi (Screen) is only useful for thumbnails. Because rasterising is irreversible, it is always safer to render higher than you think you need and scale down later.
Can I edit or search the text in the PNG?
No. The text has become pixels. Nothing in a PNG is searchable or selectable. To get real, editable characters out of a PDF, convert it to TXT — Convexy pulls out the document's actual text layer. Turning a picture of text back into text requires OCR, which Convexy does not do.
Why is the PNG file so large?
Because you are storing a high-resolution page losslessly. A 300 dpi render of an A4 page is roughly 2480 x 3508 pixels, and PNG discards nothing. That is the price of clean text. Drop to 150 dpi if the size is a problem, or use JPG if the page is photographic and a little compression noise is acceptable.