How to convert TIFF to JPG on iPhone
TIFF is what scanners, fax archives, print shops and museums produce. It is also, frequently, enormous — which is usually why you are here. JPG will cut it by an order of magnitude, at a cost worth understanding.
TIFF is a container, not a single format
This is the thing people miss. TIFF (Tagged Image File Format, 1986) is a flexible wrapper. A .tif file might contain:
- Completely uncompressed pixel data — three bytes per pixel, no compression at all. This is why a scanned A4 page can be 100+ MB.
- LZW or ZIP compressed data — lossless, moderately effective.
- CCITT Group 4 — a bilevel scheme for black-and-white document scans and faxes.
- Occasionally even JPEG-compressed data, inside a TIFF wrapper.
- Multiple pages, one per scanned sheet.
- 16 bits per channel, CMYK, alpha channels, colour profiles — TIFF supports all of it.
So “how big is a TIFF” and “is TIFF lossless” have no single answer. In practice, the ones landing on your phone are usually lossless and very large, which is exactly the problem JPG solves.
Multi-page TIFFs: you get the first image only. A JPG holds exactly one image. If your TIFF is a multi-page scan, Convexy converts the first page. There is no way for a single JPG to hold ten scanned sheets — that is simply not what the format is. If you need every page, a multi-page PDF is the right target, not a JPG.
The tradeoff
- Size: the win, and it is huge. An uncompressed TIFF converted to a high-quality JPG typically drops by 90–95%. A 120 MB scan becomes a few megabytes.
- Quality: JPG is lossy — it permanently discards detail. On a photographic scan at a high quality setting, that loss is invisible. On a scan of text or line art, it is not: JPEG compression puts ringing and speckle around sharp high-contrast edges, which is precisely what printed letters are.
- Bit depth: a 16-bit-per-channel TIFF becomes 8-bit. If you are colour-grading or preparing for print, that matters. For everything else it does not.
- Transparency: if the TIFF has an alpha channel, it will be flattened onto a solid background — white by default, or a colour you choose. JPG has no alpha channel.
- CMYK and colour profiles: JPG is an RGB format in practice. A CMYK print TIFF converted to JPG is no longer a print-ready file.
If the TIFF is a document scan, consider PNG instead. PNG is lossless, so the text edges stay clean — no JPEG halos around the letters — and for a black-and-white or flat-colour scan it compresses far better than you would expect. JPG is the right answer for photographic TIFFs; PNG is the right answer for text and line art.
Why you have a TIFF at all
Almost always because a machine or an institution produced it: a flatbed or document scanner, a fax archive, a print shop's artwork, a medical or scientific imaging system, a museum or library digitisation project. TIFF is the default in those worlds precisely because it is lossless, flexible and boringly stable — excellent properties for an archival master, terrible ones for emailing a picture to someone.
Which is the honest framing of this conversion: keep the TIFF as the master, and make a JPG as the copy you actually use and send.
On-device
Convexy decodes and re-encodes locally with Apple's ImageIO. No upload, no account, no server — which is doubly relevant here, because a large TIFF would be slow and painful to upload anyway, and the ones people scan tend to be documents they would rather not hand to a stranger.
How to do it
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Bring the TIFF in
Tap Browse files and pick the .tif or .tiff from Files or iCloud Drive, or share it into Convexy. Large scans may take a moment to load.
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Choose JPG
Convexy offers the formats a TIFF can become — JPG, PNG, HEIC, BMP, GIF, WebP, AVIF, ICO or PDF. Tap JPG. If the scan is text or line art, consider PNG instead.
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Set the quality
Keep it high for a scan you may need to zoom into or print. The size drop from an uncompressed TIFF is dramatic even at high quality, so there is rarely a reason to compress aggressively.
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Set a background if the TIFF has transparency
JPG cannot store an alpha channel. Transparent areas are flattened onto white unless you pick another colour in Options.
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Convert, then keep the original
Save or share the JPG. Keep the TIFF if it is an archival master — the lossy step cannot be undone, and re-converting from the master is always better than re-converting from a copy.
Common questions
Why are TIFF files so large?
Because they are frequently stored uncompressed, or losslessly compressed at best. TIFF was designed as an archival and print format, where fidelity matters and file size does not. A scan of a single A4 page at 600 dpi with no compression is well over 100 MB — that is TIFF working exactly as intended, and it is why converting to JPG can cut 90–95% of the bytes.
Is TIFF lossless?
Usually, but not necessarily — TIFF is a container, and it can hold uncompressed data, LZW or ZIP compressed data, CCITT Group 4 for bilevel scans, or even JPEG-compressed data inside the wrapper. In practice, TIFFs from scanners and archives are lossless and large. You cannot tell from the extension alone.
What happens to a multi-page TIFF?
You get the first image. A JPG is a single-image format and cannot represent multiple pages — no setting changes that. If your TIFF is a multi-page document scan and you need all of it, convert to a multi-page PDF instead; that is the format built for the job.
Should I convert my scan to JPG or PNG?
PNG if the scan is text, a form, a diagram or line art — it is lossless, so the letter edges stay sharp, and flat-colour scans compress well. JPG if the scan is photographic, or if the file must be small and a little compression noise is acceptable. JPEG's artefacts cluster around exactly the high-contrast edges that printed text is made of.
Will I lose quality converting TIFF to JPG?
Yes — JPG is lossy and permanently discards detail. On a photographic image at a high quality setting you will not see it. You will also drop from 16-bit to 8-bit per channel if the TIFF was 16-bit, and lose any alpha channel or CMYK colour. For sharing and viewing, none of that matters. For print production or archival, keep the TIFF.