Browser support
Support differs by capability and browser. This page reports only behavior documented by Chrome and Edge. The fallback column describes SDK behavior when the native API is missing.
| Package | Chrome | Edge | Fallback when the native API is missing |
|---|---|---|---|
@web-ai-sdk/prompt |
148+ · stable | 138+ · Canary/Dev · flag; OT in 150 | feature-detected fallback |
@web-ai-sdk/summarizer |
138+ · stable | 138+ · stable | feature-detected fallback |
@web-ai-sdk/translator |
138+ · stable | 148+ · stable | feature-detected fallback |
@web-ai-sdk/detector |
138+ · stable | 148+ · stable | feature-detected fallback |
@web-ai-sdk/writer |
Developer trial · local flag | 138+ · Canary/Dev · flag | feature-detected fallback |
@web-ai-sdk/rewriter |
Developer trial · local flag | 138+ · Canary/Dev · flag | feature-detected fallback |
@web-ai-sdk/proofreader |
Developer trial · local flag | 142+ · Canary/Dev · flag | feature-detected fallback |
@web-ai-sdk/webmcp |
OT from 149 · local flag | OT in 150 | feature-detected fallback |
- Stable: the vendor enables the API by default.
- Canary/Dev: an Edge preview that requires a flag.
- Developer trial: Chrome’s current status label. It is not an active public origin trial.
- OT: a public origin trial listed by the vendor.
The wrappers do not detect browser brands or versions. They check the native API and its reported availability. React hooks return status: "unavailable". Vanilla functions can throw a typed unavailability error.
Chrome specifics
Section titled “Chrome specifics”Chrome’s status table lists Translator, Language Detector, and Summarizer as stable from Chrome 138. Prompt is stable from Chrome 148. Writer, Rewriter, and Proofreader are in Developer trial.
The public origin-trial milestone windows documented on the capability pages are historical:
- Writer and Rewriter shared an origin trial from Chrome 137 through 148.
- Proofreader had an origin trial from Chrome 141 through 145.
These origin trials have ended. The current Developer trial label and localhost flags are separate forms of access.
| Surface | Current Chrome localhost setup |
|---|---|
| Writer and Rewriter | Enable #optimization-guide-on-device-model, #prompt-api-for-gemini-nano-multimodal-input, and #writer-api-for-gemini-nano; Rewriter shares Writer’s flag. |
| Proofreader | Enable #proofreader-api. |
| WebMCP | Enable #enable-webmcp-testing; production testing uses the origin trial from Chrome 149. |
Chrome documents Translator and Language Detector for desktop. The foundation-model APIs have additional platform, storage, GPU, and CPU requirements. See the Prompt hardware requirements.
Do not infer support from the Chromium engine. Check the capability page for each browser.
Edge specifics
Section titled “Edge specifics”Microsoft enables Summarizer by default from Edge 138. Prompt, Writer, and Rewriter are Canary/Dev previews from 138.0.3309.2. Proofreader is a preview from Edge 142.
Translator and Language Detector shipped in Edge 148. Edge 150 lists origin trials for Prompt and WebMCP.
Models and hardware are capability-specific
Section titled “Models and hardware are capability-specific”| Edge capability | Documented model path | Documented device-performance condition |
|---|---|---|
| Prompt | Phi-4-mini by default; optional prerelease Aion-1.0-Instruct in Canary/Dev 150.0.4070+ when “Enable prerelease on-device language model” is enabled | High or greater for Phi; Medium/Low only through the prerelease Aion path |
| Summarizer, Writer, Rewriter | Phi-4-mini by default; the Writing Assistance docs now document the same optional prerelease Aion override in Canary/Dev 150.0.4070+ | High or greater for Phi; Medium/Low only through the documented prerelease Aion path |
| Proofreader | Phi-4-mini | High or greater; Microsoft does not document an Aion override on the Proofreader page |
| Translator | Task-specific translation models | No Phi/Aion performance-class rule is documented on the Translator page |
| Language Detector | Task-specific language-detection model | No Phi/Aion performance-class rule is documented on the Language Detector page |
Microsoft does not document the Aion path for Proofreader, Translator, or Language Detector.
Current Edge preview flag labels are:
- “Prompt API for on-device language model”
- “Writer API for on-device language model”
- “Rewriter API for on-device language model”
- “Proofreader API for Phi mini”
- “Enable prerelease on-device language model” for the optional Aion override documented for Prompt and Writing Assistance
Summarizer is enabled by default. Translator and Language Detector do not use these generative-model flags.
Microsoft sources: