Which app is best for searching inside PDFs on iPhone?

Last reviewed: September 26, 2026 · Markdown version

It depends on one thing: whether you are looking inside the PDF you already have open, or trying to find out which of many PDFs holds the word. For the first, the iPhone already does the job and so does almost every PDF reader. For the second you need an app that builds an index of everything you own, and there are only a handful of those. A disclosure before the list: Adinand makes DocFind, one of the apps below. It is included, it is not put first, and its section says plainly who should pick something else.

Every description of another app here comes from that app's own App Store listing or website, read on 26 September 2026. Nothing is from memory, and no app is ranked by stars or downloads.

One PDF at a time

1. Preview, already on your iPhone

Apple's guide for the Preview app has a "Find text in a PDF" section: open the PDF, tap search, and "Enter a word or phrase in the search field." It also documents two filters, Whole Words and Match Case (Open and view PDFs and images in Preview on iPhone, read 26 September 2026). If you know which file the word is in, this costs nothing and needs no download.

2. Adobe Acrobat Reader

Among the free features, Acrobat's listing says its Liquid Mode viewer lets you "Search, navigate & adjust font size or spacing to fit your screen." Text recognition for scans ("turns scanned PDFs into searchable, editable text") appears in the part of the listing headed paid features (Acrobat Reader: PDF Editor, App Store listing, read 26 September 2026). A sound choice if you already work in Acrobat on a computer.

3. PDF Expert

Readdle's app is a reader and editor first. Its listing puts search inside reading ("search text in any document"), next to annotation, form filling and signing (PDF Expert: Editor & Reader, App Store listing, read 26 September 2026). The listing does not describe a search that runs across a whole library at once, so pick it for working inside documents rather than for hunting through a folder of them.

Across a whole library

4. Spotlight and the Files app

Apple's Files article describes its search field for finding files by name: "To search for a file name, use the search field in the Files app" (Find files on your iPhone or iPad, read 26 September 2026). Spotlight's index covers "a wide range of content such as documents" and is "a local, private index that stays on your device" (About Spotlight indexing and search results on Apple devices, read 26 September 2026). Neither of those two pages says whether the words inside a PDF kept in Files are part of that index. Test it with a word you know is in one of your files before relying on it.

5. PDF Search

The most feature-rich option on this list. Its listing says it "reads every word of every document you own", ranks each page, shows results "grouped by document, with every matching page and its rank", and indexes Word, PowerPoint and iWork files as well as PDFs. It also matches word forms, so by its own example a search for hike finds hiking, and it offers an AI Chat that answers questions with page references (PDF Search: AI Chat & OCR, App Store listing, read 26 September 2026). The same listing places search inside images and scans, word-form matching and every ranked result beyond the first under Pro. The AI Chat needs Apple Intelligence hardware, and part of it can run on Apple's Private Cloud Compute, according to the listing.

6. easySearch

The widest net for file types and locations. easySearch says it can "Search for text in files stored on your device, in iCloud, Dropbox, OneDrive, network and external media", and its format list runs from PDFs "(including image-only PDFs)" to Office, iWork, EPUB and DRM-free Kindle files (easySearch - File Search Tool, App Store listing, read 26 September 2026). A good fit when your documents are spread across several cloud drives and not all of them are PDFs.

7. DocFind (ours)

DocFind does one job: search inside many PDFs at once. Results show the file, the page and the surrounding text, and a tap opens that PDF at that exact page with your keywords highlighted. Scanned PDFs are read on the phone and then searched like any other document; matches that came from that recognition carry a label, and pages it could not make searchable are reported. Indexing, searching and reading scans all work with no internet connection, and the documents never leave the iPhone. There is no account to create, and no ads, analytics or tracking.

Where it does not fit, stated plainly:

PDFs only. If half your library is Word files or ebooks, PDF Search or easySearch cover more.
Exact words, no stemming: a search for "running" will not find "run". If you want word forms matched for you, PDF Search's listing offers that.
No chat and no summaries. You type words; it shows where they are. If you want to ask a question in plain language, look at PDF Search or Nemos.
Scans are read as printed text; handwriting is not recognised. Scanned Hindi or other Devanagari pages do not become searchable.
There is no sync: the index stays on the phone that built it. On iOS it is an iPhone app.

The free tier is one library of up to 25 documents, 10 scanned pages and 10 exports every month, with unlimited keywords and results. A demo with sample documents, a scanned receipt among them, runs without setup.

If what you really want is to ask questions

Nemos

Nemos is not a PDF app first; it is a place to save voice notes, links, screenshots and files. Its listing says imported PDFs and documents sit "alongside everything else, searchable by what's inside them", and an assistant answers "from what you've saved, quoting the note, screenshot or link it came from" (Nemos: Voice Recorder & Notes, App Store listing, read 26 September 2026). Worth a look if your PDFs are one kind of thing among many you want to find again, rather than the whole collection.

The short version

Know which file it is in? Use Preview. Documents in many formats or many clouds? easySearch or PDF Search. Want answers rather than matches? PDF Search's chat or Nemos. A pile of PDFs, some of them scans, that you want searched on the phone with nothing uploaded? That is the case DocFind was built for.