Chrome Prompt API
Browser API in Developer tools
More people criticize it than recommend it. Free, on-device AI for web pages with no server costs or quotas, suited to privacy-focused and structured-output tasks. Main caveat: fingerprinting and multi-gigabyte model downloads.
8 people recommended Chrome Prompt API in Hacker News comments, 6 had mixed feelings and 23 criticized it, November 2025 to October 2026.
4 of the 8 people who recommend it commented in one thread, “The Prompt API”.
Summary written by Claude from the comments below.
37 people gave an opinion
- recommend it
- 8
- mixed feelings
- 6
- warn against or regret it
- 23
The record
Recommended in 4 of 12 months
In 4 different threads.
- November 2025: not recommended
- December 2025: not recommended
- January 2026: not recommended
- February 2026: not recommended
- March 2026: not recommended
- April 2026: recommended
- May 2026: recommended
- June 2026: recommended
- July 2026: not recommended
- August 2026: recommended
- September 2026: not recommended
- October 2026: not recommended
Why it doesn’t carry the badge
- 8 people recommend itNeeds 10 or more, not met.
- 0.3 recommenders for every criticNeeds 2 to 1 or better, not met.
- Recommended in 4 of 12 monthsNeeds 4 or more, met.
- Recommended in 4 threadsNeeds 5 or more, not met.
- The biggest thread supplies 50% of its recommendersNeeds half or less, met.
The same rules apply to every product, and the badge can’t be bought. Mixed feelings count toward neither side. How the badge works
What people say about it
Reasons grouped from a sample of 40 of the 43 opinions about it, picked in proportion to how many people recommend it, have mixed feelings and criticize it. Each mark is one comment in the sample. Open a reason to read what they said.
What people warn about
Each mark is one comment
Fingerprinting and privacy risk
“This will be a new source of fingerprinting information and this is difficult to fake to fool fingerprinting scripts”
Comment from 30 Apr 2026 in “Mozilla's Opposition to Chrome's Prompt API” “This outright non-feature is a significant source of issues, least of which is fingerprinting.”
Comment from 30 Apr 2026 in “Mozilla's Opposition to Chrome's Prompt API” Web scope and precedent concerns
“We don't need the browser to have a Prompt API to enable web applications to have goofy chatbots lurking in the corner.”
Comment from 30 Apr 2026 in “Mozilla's Opposition to Chrome's Prompt API” “It is non-obvious that adding an LLM to a web browser makes anything better for the web browser user.”
Comment from 30 Apr 2026 in “Mozilla's Opposition to Chrome's Prompt API” Inconsistent behavior across browsers and models
“when each browser has a different model attached to this API testing becomes even more a nightmare”
Comment from 27 Apr 2026 in “The Prompt API” “a model update will work entirely differently and break the existing implementations”
Comment from 30 Apr 2026 in “Mozilla's Opposition to Chrome's Prompt API” Model too limited for longer tasks
“that is ~9% of the total available disk space for baseline phones and laptops for a model that is not that useful”
Comment from 27 Apr 2026 in “The Prompt API” “The model this uses is useless for anything beyond 2 round chat at the most.”
Comment from 27 Apr 2026 in “The Prompt API”
Why people recommend it
Each mark is one comment
Structured JSON output and tool calling
“leading to model quality improvements, language support expansion, API additions like structured responses and tool use”
Comment from 30 Apr 2026 in “Mozilla's Opposition to Chrome's Prompt API” “if you have a use case that needs constrained JSON output for example, it's pretty neat”
Comment from 10 May 2026 in “Local AI needs to be the norm” “particularly because it has tool-calling builtin & structured output”
Comment from 27 Apr 2026 in “The Prompt API” Free, no server costs or quotas
“the upsides of on-device (e.g. zero-cost, permission-less start with no quotas/infra, network-resilience, privacy) make it a compelling trade-off”
Comment from 28 Apr 2026 in “The Prompt API” “The main win is that it's free and privacy preserving”
Comment from 27 Apr 2026 in “The Prompt API” Small reasoning on user data
“I've integrated these into my workflows where a tiny but non zero amount of reasoning is needed”
Comment from 2 Jun 2026 in “Chipotlai Max” “it shines in constrained environments where the model is transforming user-owned data”
Comment from 10 May 2026 in “Local AI needs to be the norm”
What people said
40 of the 43 opinions about it, picked in proportion to the three counts, newest first. Each links to the original comment.
“The Web Platform is great for agents, especially given the browser already is the user's agent itself.”
“I've integrated these into my workflows where a tiny but non zero amount of reasoning is needed”
“No local model, no webpage; more, better and cheaper adtech extortion/surveillance for vendors”
“if you have a use case that needs constrained JSON output for example, it's pretty neat”
“it shines in constrained environments where the model is transforming user-owned data”
“This comment sure didn't age well”
“The whole Prompt API is poorly designed.”
“it really doesn't answer most of the important questions”
“Having it on by default serves this goal.”
“This API is the best basis we have to allow this negotiation to happen”
“It is non-obvious that adding an LLM to a web browser makes anything better for the web browser user.”
“This outright non-feature is a significant source of issues, least of which is fingerprinting.”
“Why is that something a web page should expect to have a right to?”
“I don't want a web browser creating/running an LLM instance as that machine may not have the capability or capacity to run an LLM instance.”
“It would be better if this were all interoperable.”
“a model update will work entirely differently and break the existing implementations”
“This will be a new source of fingerprinting information and this is difficult to fake to fool fingerprinting scripts”
“This is a way for web services to make your computer complete large amounts of compute at their behest.”
“But I believe it's a difference of degree, not kind.”
“has some advantages like being a little simpler for some things”
“Prompt APIs with potential attack injection vectors are cool”
“leading to model quality improvements, language support expansion, API additions like structured responses and tool use”
“What makes this acceptable Tech”
“We don't need the browser to have a Prompt API to enable web applications to have goofy chatbots lurking in the corner.”
“The objections seem clear: tight-coupling of prompts to models, and model neutrality in the TOU.”
“It’s them articulating clear and logical reasons why the proposed API, in its current state, is bad for web interoperability”
“I think this API is probably fine, but only if the user already has a model downloaded and wants these features.”
“There is nothing worth standardizing.”
“the upsides of on-device (e.g. zero-cost, permission-less start with no quotas/infra, network-resilience, privacy) make it a compelling trade-off”
“on-device is the right move for this class of use cases”
“AI that is slow, crappy and hallucinates all the time”
“the models on most standard PCs are both tiny and slow”
“when each browser has a different model attached to this API testing becomes even more a nightmare”
“way worse than API calls both in terms of quality and speed”
“quite a nice fit with our static site”
“Also much better than every website wanting its own 22 GB rather than the 22 GB being a shared resource.”
“particularly because it has tool-calling builtin & structured output”
“that is ~9% of the total available disk space for baseline phones and laptops for a model that is not that useful”
“The model this uses is useless for anything beyond 2 round chat at the most.”
“The main win is that it's free and privacy preserving”
Counts come from 1,791,911 Hacker News comments labeled by Claude, November 2025 to October 2026, with data through October 31, 2026. Counts updated 2 Nov 2026. How we count. Report a mistake.