CIRCØ is a free, browser-based offline AI translator powered by on-device neural machine translation across 200+ languages. Run Meta's NLLB-200 model directly inside your browser tab. Your translations remain 100% private in Offline & Local-First modes — no software install, no cloud API fees, and no account required.
Traditional translation services send every paragraph and book you read to remote cloud servers. CIRCØ provides two distinct translation modes to balance performance, battery life, and complete data privacy:
Edge First (Default): Uses high-speed edge cloud functions when connected to conserve your device's CPU and battery. If your internet disconnects or an edge request fails, CIRCØ automatically falls back to your local offline AI model.
Local First (Privacy & Data Saver): Executes all lookups 100% on-device inside a sandboxed Web Worker. Zero text leaves your computer or phone, and telemetry events sent to the live dashboard redact words and sentences entirely.
In Local-First mode, reading content and translation queries never touch external servers. Anonymous aggregate telemetry on /live tracks operational uptime without collecting user text or reading history.
Offline requirements and setup
To translate without an active internet connection, CIRCØ downloads an 8-bit quantized neural model (~900 MB) once into your browser's persistent CacheStorage.
After this one-time setup finishes, you can disconnect from Wi-Fi and translate foreign-language books, academic papers, and video subtitles entirely offline. A modern web browser (Chrome, Edge, Firefox, or Safari) and at least 4 GB of device RAM are recommended. Because of strict iOS memory ceilings, iPhones and iPads automatically use fast edge cloud translation to prevent browser crashes.
Device compatibility and hardware tiers
CIRCØ executes on-device neural translation using WebAssembly SIMD and WebGPU. Real-world performance scales with your hardware capabilities:
Tier A — Modern desktops and laptops (WebGPU)
Single-word lookups: ~120–150 ms typical latency.
Phrases and sentences: ~320–420 ms typical latency, delivering an estimated 50–70 tok/s hardware-accelerated throughput depending on your graphics processor.
Zero network delay: 0 ms round-trip time eliminates cloud transmission latency entirely.
Tier B — Standard computers and laptops (WASM SIMD)
Single-word lookups: ~180–220 ms typical latency.
Phrases and sentences: ~500–680 ms typical latency, delivering a verified baseline of 42 tok/s using multi-core WebAssembly instructions.
Broad compatibility: Runs on standard laptops without requiring a dedicated graphics card.
Tier C — Supported mobile devices (Android)
Single-word lookups: ~250–380 ms typical latency.
Phrases and sentences: ~750–1100 ms typical latency with 25–35 tok/s on modern multi-core mobile processors.
Gated devices (iOS Safari and devices under 4 GB RAM)
Automatic cloud mode: Automatically routes through high-speed edge cloud translation (~250–450 ms) to prevent WebKit memory termination while keeping reading smooth.
Multi-word phrase translation: Highlight full sentences or idioms for context-aware neural translations.
Synchronized video subtitle translation: Translate subtitles in real time for local video files and YouTube videos.
Text-to-speech pronunciations: Listen to authentic voice pronunciations powered by neural speech engines.
One-tap vocabulary tracking: Save words as you read and review them anytime with spaced repetition in Vocabulary Quest.
Seamless edge fallback: If you are online while the local model initializes, CIRCØ uses edge translation so your reading is never delayed.
How CIRCØ compares to cloud translation services
As of September 2026, leading cloud translators process text on remote servers. Here is how CIRCØ compares:
CIRCØ: 100% on-device AI translation across 200+ languages in Local-First mode. Free, private, no account, runs directly in your browser.
Google Translate: Cloud-based translation across 130+ languages. On-device offline mode is restricted to mobile native apps and requires platform installations.
DeepL: Cloud-based translation across 30+ languages requiring server transmission for all lookups and paid subscriptions for unlimited volume.
Frequently asked questions
How does offline translation work in the browser?
CIRCØ runs Meta's NLLB-200 neural translation model directly on your device using WebAssembly SIMD and WebGPU. All calculations happen inside a background Web Worker in your browser, so no text is sent to external servers.
How much storage space does the offline model require?
The 8-bit quantized model requires approximately 900 MB of one-time download, stored securely in your browser's persistent CacheStorage. You can clear the cached model anytime in Settings.
Which languages are supported for offline translation?
CIRCØ supports direct translation between 200+ languages and dialects via NLLB-200. This includes all 20 interface languages, plus major European, Asian, African, and Middle Eastern languages, without routing through English.
Aymara (Latin)Guarani (Latin)🇭🇹 Haitian CreolePapiamento (Latin)Quechua
Classical & Constructed3 languages
Esperanto🇻🇦 LatinSanskrit
Can I use offline translation on iPhone or iPad?
iOS Safari enforces strict memory ceilings that prevent large neural models from running reliably. To prevent browser tab crashes, iOS devices automatically route through high-speed edge cloud translation instead.
What happens if I go offline before downloading the model?
Offline translation requires completing the one-time model download while connected. If you go offline without the model, offline lookups cannot run until you reconnect to download the model.
What data leaves my device in Local-First mode?
In Local-First mode, zero text or reading content leaves your device. Telemetry events reported to the live dashboard redact words and sentences entirely, preserving total reading privacy.
Is CIRCØ's offline translator free?
Yes. CIRCØ is 100% free with no subscriptions, accounts, or daily lookup quotas.