Comparison

PDF Viewer by Nutrient vs Hi Assistant

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

PDF Viewer by Nutrient

Easily view, search, and annotate PDF documents on your iPhone and iPad. Import files from cloud services, fill out forms, add signatures, and organize your documents. Advanced features like redaction and combining documents are available with a Pro subscription.

Highlights
  • View and search PDFs
  • Annotate with highlights and notes
  • Sign documents digitally
  • Fill out PDF forms
  • Organize and share documents
  • Import from cloud services
Features
Read full description

PDF Viewer is a fast and beautiful app, allowing you to view, search, and annotate PDF documents with ease on your iPhone and iPad. Access your files from iCloud, Dropbox, Box, OneDrive, Google Drive or any other cloud solution via Apple's familiar Document Browser interface. +++ Listed as “Productivity lifesaver” on the App Store +++ "A streamlined interface packed with powerful features - it’s like having a desktop-quality PDF toolkit wherever we go" – App Store Editor Notes “I'm impressed by how the folks at PSPDFKit have been able to fine-tune the document browser to the app's needs.” – MacStories.net "If you want a PDF viewer that is designed for reading PDF books, this is it." – App Review VIEW DOCUMENTS ON THE GO • Easily import a PDF from your favorite cloud service provider, email, or directly off a website. • Supports Open In Place, Drag & Drop and features the familiar Apple Document Browser interface from the Files app. • Search for the exact text you are looking for within the document. • Double tap on the screen to Smart Zoom directly to the text you want to read. • Annotate images (JPEG, PNG) non-destructive, just like PDF documents. (PRO) ANNOTATE WITH EASE • While reviewing a document, use your finger or Apple Pencil to highlight and markup text. • Leave comments by adding a note, text, or drawing directly on the PDF. • Add images or audio. • Reply to notes. (PRO) SIGN DOCUMENTS ANYWHERE • Add your signature to any document using your finger or Apple Pencil. • Move and resize your signature as needed. • Flatten a document to ensure the signature doesn’t change. CREATE AND EDIT PDFs • Create new documents from existing documents by moving, rotating, deleting, or adding new pages. • Combine multiple documents into a single one. (PRO) • Add bookmarks to easily return to certain pages in large documents. FILL OUT FORMS • Quickly fill out PDF Forms by adding text to the fields. • Flatten and secure the form once you’re done to ensure the document doesn’t change. • Add a signature to any Form. STORE, ORGANIZE AND SHARE • Store documents, create folders and organize your documents. • Share documents by printing, emailing or saving your edits back any cloud service. PASSWORD PROTECT DOCUMENTS • Read document metadata, title and keywords. • Protect documents with user and owner passwords and limit permissions. (PRO) AND SO MUCH MORE • Conveniently switch to night mode when viewing your documents at night. • Present on external screens without the distraction of toolbars. (PRO) • Have the text from a PDF read out loud to you with text-to-speech. • PDF Viewer remembers where you were down to the page/position where you left off - even across devices. PRICING PDF Viewer comes with a large feature set, completely free. Some advanced features require the purchase of PDF Viewer Pro, available as a subscription. We offer 3-monthly and yearly subscription plans. There’s also a fully functional 7-day trial, so you can test PDF Viewer Pro (including document merging and password editing) before you commit. All plans unlock the app on iPhone and iPad. TRUSTED BY COMPANIES YOU KNOW PDF Viewer is built on top of and powered by PSPDFKit, the same PDF engine trusted around the world by companies like Dropbox, Box, IBM, Atlassian, SAP, and Lufthansa. BE PART OF THE PDF VIEWER COMMUNITY pdfviewer.io twitter.com/pdfviewerapp LEGAL Duration and price of each subscription are displayed in PDF Viewers’ storefront, updated at the time of purchase. Payment will be charged to iTunes account at confirmation of purchase. Subscriptions automatically renew unless auto-renew is turned off no later than 24 hours before the end of the current period. Subscriptions and auto-renewal can be managed/turned off in the iTunes account settings. Any unused portion of a free trial period is forfeited as soon as a subscription is purchased. Terms of Use: https://pdfviewer.io/terms Privacy Policy: https://pdfviewer.io/privacy

About

Hi Assistant

This AI-powered assistant uses natural language processing to engage in human-like conversations. It can help with writing, programming, research, translation, and creative tasks by understanding prompts and providing detailed responses.

Highlights
  • Natural language conversation
  • AI-driven responses
  • Writing assistance
  • Programming help
  • Research support
  • Language translation
Features
Read full description

Hi Assistant - a natural language processing engine driven by AI technology that allows you to converse like a human and moreover it has a remarkable ability to interact in the form of conversational dialogue and give the responses are surprisingly human. The app allows users to input a prompt and receive a response, making it a useful tool for writing, programming, and research. With its advanced language understanding capabilities, Hi Assistant can assist with tasks such as language translation, question answering, and even creative writing. Give it a try and see how it can enhance your workflow. We would adore hearing all of your suggestions on how to make our app better. Terms of Service: https://chat.hias.app/terms-of-use.html Privacy Policy: https://chat.hias.app/privacy-policy.html Contact: hello@hadesker.net

Screenshots

PDF Viewer by Nutrient4 screens
Hi Assistant4 screens

Verdict

The call

The clearest difference is review sentiment: PDF Viewer by Nutrient at 73% against Hi Assistant's 30%. PDF Viewer by Nutrient also leads on rating (4.6 vs 3.3) and ads (none vs shown). Hi Assistant's advantage is update cadence (every 2 weeks vs monthly) and iOS requirement (15.1 vs 17.0). On price, in-app purchases, monetization model and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. PDF Viewer by Nutrient sells 2 in-app purchases, starting at $6.99 per 3 months and Hi Assistant sells 7 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

PDF Viewer by Nutrient holds the better App Store score, 4.6 against 3.3. That said, the two scores are not equally well evidenced: PDF Viewer by Nutrient has 9.1K ratings behind it against 27, so its average is the more settled of the two. Written reviews point the same way: 73% of PDF Viewer by Nutrient's written reviews are positive against 30% of Hi Assistant's.

UpkeepUpdate frequency

PDF Viewer by Nutrient ships an update monthly, Hi Assistant every 2 weeks. The most recent releases landed on October 23, 2026 and October 19, 2026 respectively.

Scorecard6 real differences · 4 level
PDF Viewer by Nutrient versus Hi Assistant: the parameters behind the verdict, then further details
ParameterPDF Viewer by NutrientHi Assistant
PriceFreeFree
Rating4.6 (9.1K ratings) — better3.3 (27 ratings)
Positive reviews73.4% of reviews — better30.0% of reviews
Number of ratings9.1K — better27
Update frequencyMonthlyEvery 2 weeks — better
AdsNo — betterYes
In-app purchasesYesYes
MonetizationFreemiumFree with in-app purchases
DevicesiPhone, iPad, Mac, Vision Pro — betteriPhone, iPad, iPod
Requires iOS17.015.1 — better
Further details — not scored
Size109 MB33 MB
Age rating4+4+
DeveloperPSPDFKit GmbHHien Nguyen

Customer experience

PDF Viewer by Nutrient

All ratings9,101 ratings
Positive90.8%
Neutral3.7%
Negative5.4%
Written reviews1,092 reviews
Positive73.4%
Neutral9.7%
Negative16.9%

Hi Assistant

All ratings27 ratings
Positive55.6%
Neutral3.7%
Negative40.7%
Written reviews10 reviews
Positive30.0%
Neutral10.0%
Negative60.0%

Bugs and requests

PDF Viewer by Nutrient

Reported bugs

4 issues
  • Annotations randomly disappearing or not saving
  • Incompatibility issues with certain PDF files
  • Scrolling and panning problems on large PDFs
  • Unexpected crashes after iOS updates

Requested features

5 requests
  • Add a rubber/eraser tool for annotations
  • Implement a side-by-side PDF view mode
  • Improve palm rejection and gesture support
  • Allow customization of toolbar and shortcuts
  • Provide better options for PDF file management

Hi Assistant

Not enough reviews yet to summarise bugs or requests.

In-app purchases

2 purchases

PDF Viewer by Nutrient

Subscriptions2
  • PDF Viewer Pro 3 Months7 Days trial$6.993 Months
  • PDF Viewer Pro Yearly7 Days trial$19.991 Year
7 purchases

Hi Assistant

Subscriptions3
  • 1 month3 Days trial$9.991 Month
  • 6 months3 Days trial$39.996 Months
  • 12 months3 Days trial$69.991 Year
One-time4
  • 50 questions$0.99
  • 80 questions$1.99
  • 10.000 tokens$2.99
Show 1 more
  • 20.000 tokens$4.99

Questions

Is PDF Viewer by Nutrient free?
PDF Viewer by Nutrient is free to download, with in-app purchases available.
Is Hi Assistant free?
Hi Assistant is free to download, with in-app purchases available.
Which has better reviews, PDF Viewer by Nutrient or Hi Assistant?
PDF Viewer by Nutrient is rated higher. PDF Viewer by Nutrient averages 4.6 out of 5 from 9.1K ratings, while Hi Assistant averages 3.3 from 27 ratings.
Do PDF Viewer by Nutrient or Hi Assistant have ads?
Hi Assistant shows ads; PDF Viewer by Nutrient does not.
Which is updated more often, PDF Viewer by Nutrient or Hi Assistant?
PDF Viewer by Nutrient ships an update monthly, and Hi Assistant every 2 weeks. Most recently, PDF Viewer by Nutrient was updated on October 23, 2026 and Hi Assistant on October 19, 2026.

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