Comparison

nilGPT vs Celestis

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

Head to head
About

nilGPT

This AI chat companion prioritizes your privacy with end-to-end encryption and secure hardware enclaves. It offers various modes like wellness and personal assistance, providing a confidential space for your thoughts and concerns.

Highlights
  • Private and secure AI chat
  • Encrypted chat data
  • AI runs in secure hardware enclaves
  • Multiple AI modes (wellness, personal assistant)
  • Confidential conversations
  • Mobile-based chat experience
Features
Read full description

nilGPT is your private, secure AI chat companion built to keep your personal conversations truly confidential. With nilGPT: - Your chat data is encrypted and split across multiple nodes, so no single server can see the full content. - The AI runs inside secure hardware enclaves, meaning even the service provider cannot access your queries or history. - You get access to multiple modes - like wellness assistant, personal assistant and companion - for a versatile chat experience without compromising privacy. All of this available as a mobile-based chat, letting you engage in judgement-free conversations, whether you’re dealing with emotional issues, relationship concerns, or simply want a private space to think out loud.

About

Celestis

This AI assistant empowers professionals with private, on-device intelligence for document analysis and knowledge retrieval. It offers offline capabilities, custom AI models built from your data, and supports various AI providers for ultimate flexibility and data sovereignty.

Highlights
  • On-device AI with Apple Intelligence
  • Offline AI capabilities
  • Private Capsules for custom AI models
  • Support for multiple AI providers
  • Near 100% accurate, sourceable answers
  • Document ingestion from various formats
Features
Read full description

Celestis: Private AI for Your Documents Your Knowledge. Your Data. Your AI. Celestis is an intelligent AI platform built for professionals who demand accuracy, privacy, and the freedom to work anywhere. Whether you're on a factory floor, aboard an aircraft, in a maintenance bay, or off the grid, Celestis brings full AI power to the edge and even completely offline. Celestis doesn't just chat. It understands your documents, learns from your knowledge, and delivers near 100% accurate, sourceable answers powered by an Adaptive-RAG engine. AI to the Edge: Offline. Anywhere. Always. Celestis Mobile supports on-device AI powered by Apple intelligence, letting you take your AI-powered knowledge completely offline. Get instant, accurate answers no matter where you are. - Maintenance technicians accessing service manuals in remote facilities - Factory workers querying procedures on the shop floor - Airline crews referencing documentation at 35,000 feet - Field engineers troubleshooting without a data connection Your knowledge travels with you. No Wi-Fi. No cell signal. No problem. Private Capsules: Your Data, Your Environment Capsules are the heart of Celestis. Each one is a self-contained, domain-specific AI built from your own documents. Private Capsules go further, running entirely in your environment for total data sovereignty. - Upload PDFs, Word docs, spreadsheets, presentations, CSVs, images, Markdown, and more - Combine Capsules into Pods for cross-domain AI with intelligent routing - Add custom instructions and guardrails per Capsule or Pod - Schedule automatic re-ingestion to keep your AI current Celestis never trains on your data. Your documents are never shared or retained beyond what you authorize. Choose Your AI Provider: Zero Vendor Lock-In Celestis ships ready to use with leading AI models, no API key required or bring your own. - Built-in: Celestis, ChatGPT, Claude, Grok - Open source: Any OpenAI-compatible endpoint - Local LLMs: Ollama and any locally-run model for complete privacy with zero cloud dependency Mix and match providers per Capsule. What Sets Celestis Apart - Near 100% Accuracy: Adaptive-RAG blends semantic and keyword search so every answer is precise and sourceable - On-device AI with Apple Intelligence - Powered by Apple Silicon in the cloud and green datacenters - Reader Mode: Read documents while asking questions in a seamless split view - Super AI: Augment Celestis with your Capsules to create a personalized AI that knows your domain - Simple Credit Pricing: No token math. Credits per action type, in the app or via API - Replicas Marketplace: Publish your Capsules, earn credits when others use your knowledge, creators keep 70% - Connectors: Source knowledge from Gmail, Google Drive, Notion, Slack, or any REST API Key Features - Chat with Celestis AI, always free to start - Domain-specific AI Capsules built from your documents - Offline AI Bundles for full AI access with no internet - Private Capsules running entirely in your environment - Audio Conversations and Text-to-Speech - Bring Your Own Model: ChatGPT, Claude, Grok, Ollama, and more - Capsule Collections with intelligent cross-domain routing - Reader Mode for side-by-side document reading and querying - Image generation and transformation - Live search and deep research - Connectors that connect to your MCP Servers, providing limitless data sources - Team collaboration with shared Capsule pools - Full API access for custom integrations - Analytics for Capsule performance, credit spend, and replica earnings Terms of Service: https://celestis.ai/terms-of-service Privacy Policy: https://celestis.ai/privacy-policy

Screenshots

nilGPT2 screens
Celestis4 screens

Verdict

The call

The clearest difference is rating: Celestis at 5.0 against nilGPT's 3.0. Celestis also leads on update cadence (every 2 weeks vs every 4 months). nilGPT's advantage is iOS requirement (15.1 vs 26.0). On price, review sentiment, ratings volume and ads 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. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Celestis holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 2 and 4 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

UpkeepUpdate frequency

nilGPT ships an update every 4 months, Celestis every 2 weeks. The most recent releases landed on November 5, 2026 and October 31, 2026 respectively.

Scorecard3 real differences · 7 level
nilGPT versus Celestis: the parameters behind the verdict, then further details
ParameternilGPTCelestis
PriceFreeFree
Rating3.0 (2 ratings)5.0 (4 ratings) — better
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings24 — better
Update frequencyEvery 4 monthsEvery 2 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPodiPhone, iPad
Requires iOS15.1 — better26.0
Further details — not scored
Size40 MB3.0 GB
Age rating12+12+
DeveloperNillionCelestis Ai Inc

Customer experience

nilGPT

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Celestis

All ratings4 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews3 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

nilGPT

No in-app purchases

None

Celestis

No in-app purchases

Questions

Is nilGPT free?
nilGPT is free to download, with no in-app purchases.
Is Celestis free?
Celestis is free to download, with no in-app purchases.
Which has better reviews, nilGPT or Celestis?
Celestis is rated higher. nilGPT averages 3.0 out of 5 from 2 ratings, while Celestis averages 5.0 from 4 ratings.
Do nilGPT or Celestis have ads?
Neither nilGPT nor Celestis shows ads.
Which is updated more often, nilGPT or Celestis?
nilGPT ships an update every 4 months, and Celestis every 2 weeks. Most recently, nilGPT was updated on November 5, 2026 and Celestis on October 31, 2026.

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