CoPilot Interview vs ExtraBrain: Bring-Your-Own-Model Desktop Copilot vs Included Models

ExtraBrain and CoPilot Interview differ mainly in who supplies the AI model. ExtraBrain is a free, local-first desktop copilot for Mac and Windows that runs an on-device model (Gemma) or your own provider keys, with Pro from $9.99 a month; CoPilot Interview includes its models in the plan, from a free tier with 15 minutes of live help a day up to Pro+ at $49.99 a month. Below: a side-by-side as of October 26, 2026, the honest trade-offs of bringing your own API keys, and who each tool suits.

What each tool is

ExtraBrain is a desktop app for Mac and Windows, with Linux planned. It runs on your computer and does not join calls as a bot, and offers live transcription, screen-aware context and suggested answers. Its site lists Zoom, Google Meet, Microsoft Teams, Webex, Amazon Chime, Lark/Feishu, Slack Huddles and Discord, plus HackerRank, CoderPad, Codility and CodeSignal. There is an Android phone controller for the Mac app, with iOS in progress. The free tier is described as always free, with on-device AI (Gemma), bring-your-own-provider keys, local transcripts and notes, and local transcription. Pro adds automatic answers, custom profiles, post-session summaries, session insights and top-tier models with your own keys.

CoPilot Interview is a desktop app for Windows 10 and 11 and macOS 12 and later. It listens to the computer's audio output and your microphone, never joins the meeting, and sends the transcribed text to a model we supply: Mercury 2.5 by Inception on Free, GPT-6 Luna on Pro, and Claude Haiku 5.5 and Gemini 3 Flash on Pro+. There are no keys to manage.

Side by side (as of October 26, 2026)

Bring your own keys vs models included

Bringing your own keys has real advantages. You choose any model your provider offers, and your transcripts and prompts go to an account you control under terms you agreed to directly. ExtraBrain's on-device Gemma option goes further, at the cost of a smaller model that depends on your hardware.

The costs are less visible. You need an account with each provider, a payment method on file with them, a key stored safely on the laptop, and a spending limit set so a long session does not surprise you. Provider outages and rate limits become your problem, and support for a slow answer is split between two companies. Our page on which models power these tools explains why that matters. With CoPilot Interview the model is part of the price: the same text goes to the model you pick from the plan's list, as described on our model-picking page, and there is nothing to configure. The limit is that you choose from our list, not the whole market.

Who each tool suits

Choose ExtraBrain if you already hold provider keys and want to use them, want an on-device option, want Linux eventually, use Slack Huddles, Discord or Lark, or want a one-time Lifetime price. Its 14-day trial with no card makes testing cheap. Our open-source roundup covers other local-first options.

Choose CoPilot Interview if you would rather not manage keys or provider bills, want free scored mock interviews built from your resume, want Dual AI Mode's two included models side by side, or want Coding mode with Big-O and edge cases. Either way, follow your employer's rules: both are preparation tools first, and live help belongs only in interviews where it is permitted.

Where CoPilot Interview fits

CoPilot Interview is an AI interview assistant with the models included and preparation first: an AI interviewer built from your resume and the job description asks questions aloud and scores each spoken answer out of 10, free. Audio is streamed in short segments for transcription and is not stored on our servers; a text transcript is saved only in your Documents folder; the transcribed text goes to the model you choose. A 14-day money-back guarantee covers the first payment of a new subscription if under 30 minutes of live session time has been used. Disclosure: CoPilot Interview is our product, so weigh what we say about it accordingly.

Frequently asked questions

Is ExtraBrain really free?

Its site describes the free tier as always free as of October 26, 2026, with on-device AI (Gemma), your own provider keys, local transcripts and local transcription. Hosted models through your keys are billed by that provider. Pro is $9.99 a month with 1,000 credits, $79 a year, $29 for a 90-day Job Search Pass or $149 lifetime.

Do I need an OpenAI or Anthropic account to use ExtraBrain?

Not for the on-device Gemma model. For hosted models you supply your own provider keys, so you need an account and payment method with that provider. CoPilot Interview includes Mercury 2.5 on Free, GPT-6 Luna on Pro and Claude Haiku 5.5 and Gemini 3 Flash on Pro+, with no keys to manage.

Which is cheaper over a three-month job search?

It depends on usage. ExtraBrain's Job Search Pass is $29 one-time for 90 days of Pro, plus whatever your provider bills for hosted models. CoPilot Interview's Standard 3-month plan is $59.99 with models included, and the free plan covers 15 minutes a day for nothing.

Does either tool join the meeting as a participant?

No. ExtraBrain says it runs on your computer and does not join calls as a bot. CoPilot Interview listens to the computer's audio output and your microphone, so it works with any app that plays audio and never appears in the participant list.