How to convert PDF to TIFF on iPhone
TIFF is what you reach for when a printer, an archive or a piece of enterprise software refuses anything lossy. Convexy renders the PDF page to a TIFF at the resolution you choose, entirely on the device.
What this conversion really is
It is a render, not a translation. A PDF page is a set of drawing instructions — draw this glyph here, stroke this line there. TIFF is a grid of pixels. So the page is drawn, at a chosen resolution, and the resulting picture is written out.
Everything that made the PDF a PDF stops existing at that moment. The text becomes shapes. You cannot select a word in the TIFF, search it, or copy it. Vector artwork that stayed razor-sharp at any zoom level is now fixed at whatever resolution you rendered it. That is the trade, and it is the right trade when the receiving end wants an image and nothing else.
Convexy converts the first page of the PDF. A multi-page PDF does not produce a multi-page TIFF, and it does not produce one TIFF per page — you get a single image of page one. If your PDF has more than one page, use the free PDF Split tool first to cut it into single-page PDFs, then convert those (select several at once and the app batches them).
Resolution: the only setting that matters
The Quality option controls the rendering resolution, and it is the difference between a thumbnail and a print master:
- Screen — 72 dpi. The PDF page rendered at its nominal size, one pixel per point. A US Letter page comes out around 612 x 792 pixels. Fine for a preview or a web thumbnail, visibly soft if printed.
- Standard — 150 dpi. Around 1,275 x 1,650 pixels for Letter. The sensible default: text is crisp on screen and acceptable in print.
- High — 300 dpi. Around 2,550 x 3,300 pixels for Letter. This is the print and archive standard, and the setting to use if a print shop, a court filing system or a records department specified a dpi at all.
Resolution is not free. Every doubling of dpi roughly quadruples the pixel count.
TIFF is lossless, and lossless means large
TIFF does not throw pixels away. There is no quality slider, because there is no quality decision to make — the output is exactly what was rendered, with no compression artefacts, no smeared edges around text, no blocking in gradients. That is the entire point of the format, and it is why scanning bureaus, print workflows and long-term archives standardised on it.
The cost is size. A full-page 300 dpi TIFF is several megapixels of uncompressed image data, and it will dwarf the PDF page it came from — a text page that was 60 KB as a PDF can land in the tens of megabytes as a TIFF. Nothing has gone wrong when that happens; you asked for every pixel and you got them.
If you do not specifically need lossless, you probably want a different format:
- PNG — also lossless, far smaller for pages that are mostly text and flat colour, and readable by everything. For most people this is the better choice, and the PDF can convert straight to it.
- JPG — lossy, much smaller, with a quality slider. Right for sharing a page by email or message, wrong for archival.
- TIFF — when something upstream told you TIFF, or when a lossless master is the deliverable.
Transparency and background
The page is rendered onto a white background. PDF pages can technically be transparent in places; a page rendered for print is not, and flattening onto white is what a printer would do anyway. If you were hoping for a transparent TIFF of a logo on a PDF page, that is not what comes out.
The rendering happens on your device using Apple's PDF engine. No page of your document is uploaded, because there is nothing to upload it to — the app has no server and works with the network off. PDF Merge and PDF Split are free forever, so the multi-page workflow above costs nothing beyond the conversion itself.
A TIFF of a scan is still a scan
Worth saying because people try it: converting a scanned PDF to TIFF does not make the text readable by a computer. It was an image inside a PDF; now it is an image in a TIFF. Convexy has no OCR — see PDF to TXT for what is and is not possible there.
How to do it
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Split the PDF first if it has several pages
Open the free PDF Split tool, pick your page range, and produce single-page PDFs. Skip this if your PDF is already one page.
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Bring the PDF into Convexy
Tap Browse files and choose the PDF, or share it into Convexy from Files. Selecting several files at once sends them to the batch screen.
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Choose TIFF
The app lists only what this file can become: TXT, JPG, PNG and TIFF. Tap TIFF.
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Set the resolution
In Options, pick Quality: Screen for 72 dpi, Standard for 150 dpi, or High for 300 dpi. Use High if anyone has told you a dpi requirement.
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Convert, then save or share
Tap Convert. The result screen shows the output size next to the original so the cost of lossless is in front of you. Save to Files or Photos, or share it on.
Common questions
Does it convert every page of the PDF?
No. Convexy renders the first page and gives you one TIFF. To cover a whole document, use the free PDF Split tool to break it into single-page PDFs first, then convert those — you can select them all at once and the app runs them as a batch, one output per page.
Can Convexy make a multi-page TIFF?
No. TIFF as a format supports multiple images in one file, but Convexy writes a single-page TIFF. If your workflow specifically requires a multi-page TIFF container, this is not the tool for that step.
Why is the TIFF so much bigger than the PDF?
Because a PDF page of text is a few kilobytes of drawing instructions, and a TIFF of that page is millions of pixels stored without lossy compression. At 300 dpi a Letter page is roughly 2,550 x 3,300 pixels. Large output is the format behaving correctly. Use PNG or JPG if size matters more than losslessness.
Which quality setting should I pick?
If someone specified a dpi, match it: Screen is 72, Standard is 150, High is 300. If nobody specified anything, Standard is the sane default and High is what you want for print or archival. There is no quality slider for TIFF because the format is lossless — the only decision is how many pixels you render.
Can I still select or search the text afterwards?
No. The page has been rendered to pixels; the characters no longer exist as characters. If you want the words, convert the PDF to TXT instead — and note that only works when the PDF has a real text layer.
Is the PDF uploaded anywhere to be rendered?
No. The rendering runs on your iPhone or iPad using Apple's own PDF and imaging frameworks. There is no backend, no account and no upload — the app works with the network switched off entirely.