Ask questions, understand documents, work through problems, and write code. All on your iPhone.
Free, unlimited on-device AI. No account.
Optional cloud AI is available with Pro, with a monthly usage limit.
Offline chat
See Edsger Mini in a real conversation. Follow your curiosity with AI that runs on your phone.
Move between a conversation and a coding workspace. Follow a question, test an idea, or build a project wherever you are.
Chat & learning
Ask about code, math, science, or the subject on your mind. Attach a document, ask follow-up questions, and work through an explanation at your pace.
Editor & runtimes
Write C, Python, JavaScript, and Lua in their own project workspaces. Run programs on your device, interact with the console, and follow errors back to your code.
The agent can inspect your project, edit files, and use the app’s local runtimes. You can review the result and return to a restore point.
See the agent in actionAsk for a new program, a fix, or a change to an existing project.
The agent reads the project and makes changes within Edsger’s workspace.
Inspect the code, test it, and keep what works. Restore earlier changes when you need to.
Edsger brings third-party AI models into a workspace built for learning and coding. These are our in-app names, with the underlying models listed here.
Powered by Qwen3.5-4B
Offline chat and the local coding agent. Runs on your device without a cloud AI connection.
Powered by Liquid AI
LFM2.5-1.2B-Instruct
A smaller model for everyday offline conversations. Choose it from the Chat model menu.
Powered by DeepSeek
Cloud AI integrated with Chat and the coding agent. Internet access and sharing consent are required.
Local AI keeps inference on your device. Selecting a cloud model sends the relevant request content to its provider. Local and cloud models use the app’s available tools and runtime limits.
The editor, local runtimes, and on-device AI are free. Pro adds cloud AI, your own provider connections, and more ways to work.
$0 for local features
Start learning and building on your device.
$10 / month
Everything in Free, plus connected tools.
$25 / month
All Pro features, with a larger monthly cloud allowance.
Unlimited applies to on-device AI. Cloud use is metered by request and response size, with a monthly limit. Your remaining allowance is shown in the app. When it cannot cover another cloud request, local AI remains available.
Your API provider bills BYOK usage separately. ChatGPT and Claude consumer subscriptions do not include API usage. Prices shown are US prices; the App Store displays your regional price. Paid plans renew monthly until canceled. Manage subscriptions in your Apple Account settings.
The on-device AI models, local coding agent, editor, and four language runtimes are free. Local AI has no subscription usage cap. Optional cloud AI has a monthly usage limit; personal API connections are billed by your provider.
Edsger uses third-party models. Edsger 1.0 is powered by Qwen3.5-4B; Mini uses Liquid AI’s LFM2.5-1.2B-Instruct; Dijkstra is powered by DeepSeek. Edsger provides the app, model integration, project tools, local runtimes, and learning experience.
Pro combines cloud AI with Edsger’s Chat and project tools, plus your own OpenAI or Claude API connections, GitHub push, photos in cloud Chat, and personalization. The free app remains a useful option on its own.
Yes. After installing the app, on-device AI and the language runtimes work offline. Cloud AI, provider connections, GitHub push, and purchases require an internet connection.
Local models are smaller and their answers, speed, and memory use depend on the task and device. They can be useful for everyday questions and smaller programs. Complex work may benefit from a cloud model. Every model can make mistakes.
C uses PicoC, an interpreter rather than GCC or Clang. Python, JavaScript, and Lua run in restricted on-device environments. Package installation, desktop graphical interfaces, and network access from programs are not supported. Review AI-generated code and test it before relying on it.
Local AI processes your requests on your device. Optional cloud requests send relevant prompts, conversation context, documents, photos, project code, and tool results to the selected service after you allow sharing. Dijkstra uses Edsger’s service to connect to DeepSeek; personal API connections go to your chosen provider. GitHub receives the files you choose to push.
On-device AI remains available. Pro and Pro Plus include metered monthly cloud usage, and the app shows your remaining allowance. Allowances reset with your subscription period and do not roll over. A small balance can remain unusable if it cannot cover the reserve required to start another request.
Free on iPhone and iPad. No account needed.