How to convert JPG to PDF on iPhone
PDF is what people mean when they say “send it as a document”. Converting a JPG wraps the image in a single-page PDF — useful for receipts, forms, ID photos, homework and anything an institution insists on receiving as a PDF.
What actually happens
A PDF is a page-description document, not an image format. Converting a JPG creates a PDF containing one page, with your image drawn onto it. Convexy sizes that page to the image's own pixel dimensions, so nothing is cropped, letterboxed or stretched — the page has the same aspect ratio as the photo you started with.
This is worth knowing because it is not what every converter does. Many force the image onto a fixed Letter or A4 page and either pad it with white margins or crop it. If you specifically need a Letter-sized or A4-sized page — because it is going to be printed on physical paper — check the result and be prepared to set the page up in a document app instead.
Quality: the image is embedded, not re-photographed
The pixels from your JPG are drawn into the PDF page at full resolution. You are not losing resolution by converting — a 4000x3000 photo produces a 4000x3000-point page. What you should not expect is any improvement: a blurry or heavily compressed JPG makes a blurry, heavily compressed PDF. PDF is a wrapper, not a restoration tool.
If the source photo is small or soft, the PDF will look exactly as small and soft when someone prints it. The fix is a better source image, not a different container.
To combine several images into one multi-page PDF: convert each image to PDF (select them all at once and run a batch), then use Convexy's free PDF Merge tool to join the resulting one-page PDFs into a single document, in the order you choose. PDF Merge and PDF Split are free forever — they are not part of the paid unlock.
The common real-world jobs
- Scanned documents and receipts. Photograph the paper, convert to PDF, submit. Most expense and admin systems want a PDF and reject a JPG.
- Signed forms. Print, sign, photograph, convert. Crude, universally accepted.
- Applications and portals. Many upload forms simply refuse image formats.
- Emailing a set of photos as one file. Batch-convert, then merge into a single PDF rather than attaching fifteen images.
A photo-of-a-document PDF is not a searchable document. The text in it is pixels, not characters — nobody can select it, search it, or copy from it, and a system expecting machine-readable text will not find any. That is fine for most submissions and useless for others. Convexy does not do OCR; it does not pretend the image is text.
Privacy, since this is usually paperwork
The files people convert to PDF are overwhelmingly sensitive: bank statements, passports, medical forms, payslips, signed contracts. Those are precisely the documents you should not be uploading to an anonymous web converter in exchange for a free download link.
Convexy builds the PDF on your device with Apple's own frameworks. There is no server, no account, and no network request — it works with the phone in Airplane Mode. Photo metadata (EXIF, GPS) is stripped by default, so the PDF of your signed form is not quietly carrying your home coordinates.
How to do it
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Pick the JPG
Tap Browse files or choose from Photos. To make a multi-page document later, select all the images at once — they will run as a batch.
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Choose PDF
PDF appears in the list of formats a JPG can become. Tap it.
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Resize first if the file needs to be small
There is no quality slider when writing a PDF from an image — the picture is embedded as it is. If the PDF must fit an upload limit, set a maximum dimension in Options to shrink the source image before it is wrapped.
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Convert
You get a one-page PDF whose page matches the image's pixel dimensions.
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Merge, if you need more than one page
Open Tools, choose PDF Merge, add the PDFs you just made, and order them. The merged document is a single multi-page PDF. This tool is free and never asks for a purchase.
Common questions
How do I put multiple photos into one PDF?
Convert each photo to PDF — select them all at once and Convexy runs them as a batch — then use the free PDF Merge tool to combine the results into one document, in whatever order you like. There is no single-step “many images to one PDF” conversion; merging is the honest two-step way to do it, and it gives you control over the page order.
Will my PDF be A4 or Letter sized?
Neither by default. Convexy sizes the PDF page to the image's own pixel dimensions, so the page has exactly the photo's aspect ratio and nothing gets cropped or padded. If you need a true A4 or Letter page for physical printing, place the image into a document in a word processor or layout app instead — that is a page-layout job, not a format conversion.
Does converting JPG to PDF reduce the quality?
The image is drawn into the page at its full resolution, so you are not throwing away pixels by converting. But nothing improves either — a low-quality JPG produces a low-quality PDF. If the result looks poor when printed, the source photo was the limiting factor.
Can I search or select the text in the PDF?
No. The PDF contains a picture of text, not text. There are no characters in the file for anything to search, select or copy. Extracting real text from an image needs OCR, which is a different technology — Convexy does not do it, and does not claim to.
My PDF is too big to upload. What do I do?
Shrink the image before wrapping it. Set a maximum dimension in Options — a 4000px photo of a receipt is wildly more resolution than any reader needs, and halving the dimensions cuts the pixel count to a quarter. You can also lower the JPG's quality first and then convert that smaller JPG to PDF.
Is my document uploaded anywhere?
No. The PDF is generated on your iPhone or iPad. Convexy has no backend and makes no network calls to convert — you can verify that by turning on Airplane Mode and watching it still work. Given that JPG-to-PDF is usually applied to bank statements, IDs and signed forms, this is the part that actually matters.