On-Device AI Assistant with Voice - Ceres

Tracking since May 15, 2026.

Changelog

• Jun 3, 2026
  description

  Writing help where your cursor lives
  
  This app gives superpowers to your hands — Use AI rewriting where you actually write with just a button, dictate, and listen to summaries for any webpage, all just a button away.
  
  Here's what it can do for your everyday writing:
  
  - Fix grammar and spelling — proofread and clean up spelling, make grammar corrections and adjust tone without leaving the page.
  
  - Rewrite — make text warmer, clearer, shorter, more formal, more direct, or just easier to read
  
  - Voice-to-Text — turn your words into editable text on any website without using keyboard.
  
  - Custom Prompts — build your own writing buttons for the stuff you do over and over: customer replies, product listings, formal emails, quick cleanup jobs
  
  - Translate - translate directly from your main language to English and opposite with auto language detection.
  
  - Summary — get a speakable summary for any page while you working
  
  - Smart Crop & OCR — select an area of the page, crop it, and pull out the visible text offline into a sidebar notebook
  
  - On-device AI — when your hardware supports it, the tool uses Gemini Nano or Phi-4 Mini so everything stays private and costs nothing
  
  - Sidebar history — previous rewrites, transcripts, and suggestions stay saved so you can grab them later without redoing the work
  
  - Works anywhere — any text field in the browser: emails, forms, social posts, comments, dashboards, you name it
  
  - Custom provider fallback — if your device can't run AI locally, you can plug in your own API key and use models like GPT 5.4 mini, Gemini 3 Flash, or DeepSeek v4 Flash
  
  Who it's for
  
  This is for people who spend their day typing inside the browser — emails, support replies, social posts, listings, forms, comments, and everyday web work. It's for those moments when a sentence sounds off, a paragraph feels too long, or you just dictated a rough idea and need it shaped into something presentable without switching to another tool.
  
  It's also for people who care about privacy and don't want to pay a subscription for tasks their own machine can handle. If opening ChatGPT just to rephrase a sentence feels like overkill, this gives you a lightweight, one-time-purchase alternative that runs locally when it can and falls back to your own API key when it can't — all without leaving the page you're on. That's what Spellwand was built for.

  Ceres is a complete and open writing assistant that works inside any text field with on-device AI or any LLM you want to plug.
  
  🟣 Writing Assistant 🟣
  
  ➢ Grammar / Spelling fixes on any selected text
  
  ➢ AI rewrites - expand, condense, simplify, format or match any tone.
  
  ➢ Edits happen directly in the active field (Gmail, Docs, forms, any site) - no popups.
  
  ➢ Custom buttons with your own prompts - create one-click buttons for any task. Define your own prompt (like "make this sound like a pirate" or "convert to bullet points"), name it, and it appears in your toolbar.
  
  🔵 Accessibility 🔵
  
  ➢ Voice typing on any website with speech recognition.
  
  ➢ Offline translate back and forth to english with automatic language detection.
  
  ➢ Text-to-speech - listen to selected text.
  
  ➢ Both translate and speech listen anything to your mother language (killer feature 💀).
  
  ➢ Optical character recognition on every image or video with instant copy!
  
  ➢ Summary page with TTS speaking!
  
  🟢 More with an AI provider 🟢
  
  ➢Context-aware chat - chat with your own LLM, aware of open tabs and PDFs.
  
  ➢Instant apply chat suggestion to any page (killer feature 💀).
  
  ➢ Chat session can generate images if you configure the correct image generation model LLM (optional)
  
  ➢ Chat session can dictate with Whisper or any other audio LLM capable via API (optional)
  
  ...nearly AI Browser experience...
  
  🟠 Use cases 🟠
  
  ➢ Reply to a work email by speaking in Greek ➢ then translate to English (killer feature 💀).
  
  ➢ Clean up a messy Notion list ➢ attach to chat ➢ then make it a complete paragraph.
  
  ➢ Draft an mail by speaking raw ideas ➢ press shorter button ➢ your messy text because usable! (killer feature 💀).
  
  ➢ Fix spelling on selling articles ➢ select ➢ hit "grammar / spelling" ➢ correction appears in place.
  
  ➢ Summarize a long article  ➢ ask Ceres ➢ listen while you keep working.
  
  ➢ Re-write offline when connection drop- on-device model handles writing and voice every where.
  
  ⚪ Technology ⚪
  
  Ceres is using on-device/local AI (Gemini Nano managed by Google Chrome) for writing tasks, Tesseract for Optical Character Recognition, and browser capability for speech synthesis and speech recognition. Additionally, you can use your favorite AI provider to power the enriched Chat Copilot.
  
  ⚫ Specs ⚫
  
  Your computer must support Chrome built-in AI, suitable GPU or a CPU setup with at least 16 GB of RAM and 4 CPU cores. The first run may also need time to download the model.
  
  If browser cannot run on-device AI on your computer, you can always connect your writing buttons to an AI provider in settings. After that, Ceres will use the selected provider for these AI features.
  
  Enjoy, a Browser with Super Powers powered by your computer or choice LLM!

• Jun 3, 2026
  short_description

  AI rewriting and dictation in any text field, with custom buttons support. Powered by on-device AI or OpenAI-compatible endpoints.

  AI writing and chat assistant with speech-to-text and speech synthesis. Supports Gemini Nano, OpenAI, DeepSeek, and more.

• Jun 3, 2026
  name

  Spellwand – Writing Αssistant with On-Device AI

  On-Device AI Assistant with Voice - Ceres

• Jun 3, 2026
  permissions

  sidePanel, activeTab, storage, offscreen

  sidePanel, activeTab, storage, tabs, identity, history, offscreen, unlimitedStorage

Permissions & access

Permissions

sidePanelactiveTabstoragetabsidentityhistoryoffscreenunlimitedStorage

Host access

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Screenshots