Is Practicing English Interviews With ChatGPT Enough? ChatGPT vs Mocky.pro

Free ChatGPT is already strong: it is great for research, drafting answers, and line-by-line polishing, and it is the right first step for thinking your answers through. But to actually drill until you can say them out loud, it has gaps: it does not reliably stay in the interviewer role, full voice costs money (Plus at US$20/month), and it has no fixed question bank tied to your CV and JD, no foreign-company question data, and no structured post-interview summary. Those gaps are exactly what Mocky.pro (NT$199 one-time, voice-first) fills. The smartest move is not either/or, but using both.

We know most of our users' default alternative is "free ChatGPT." So this post neither hypes nor bashes it. It honestly breaks down where ChatGPT genuinely shines, where it stalls specifically for interview practice, and what Mocky.pro adds. For the wider tool landscape, start with our complete comparison of six AI mock interview tools.

Quick Comparison Table

Figures current as of July 2026. ChatGPT plans and voice quotas, and Mocky.pro pricing, can change, so check each official page for exact terms.

What ChatGPT Genuinely Does Well: Breadth, Drafts, and Free

If your job is "figure out what to say," ChatGPT is nearly irreplaceable, and free to use.

Researching a company, drafting three versions of "tell me about yourself" or "what is your biggest weakness," cleaning up non-native English line by line, outlining a STAR story, ChatGPT does all of it fast and well. That is the natural strength of a general-purpose large model. For most people, the first step of interview prep should be exactly this: use ChatGPT to get the content and structure of your answers right. The free tier handles most of the drafting work, which is why it is your default choice. We will not pretend Mocky does this better, because it is not our focus.

The Practice-Experience Gap: From "Can Write It" to "Can Say It"

Being able to write a good answer and being able to deliver it under pressure are two different things, and ChatGPT's gap falls squarely on the second.

Used as a mock interview tool, ChatGPT runs into a few concrete experience gaps:

• Staying in the interviewer role: after a while ChatGPT slips back into "let me analyze this question," and you have to keep reminding it to "stay as the interviewer, one question at a time." Mocky.pro is the interviewer by default, opening straight into a back-and-forth and probing the details in your answers like a real interviewer.
• Voice-first with live transcript: interviews are spoken. ChatGPT's Advanced Voice is only a short daily preview on free, and using high-quality voice for a whole session needs Plus. Mocky is voice-first from the start: you speak, the AI answers by voice, the transcript is generated live and saved to your account, and you can review and export it afterward.
• CV/JD-tailored questions: ChatGPT makes you paste your background every time and forgets it in a new chat. Mocky lets you upload your CV and JD so questions are tailored to your experience and the specific role.
• Foreign-company question banks: ChatGPT does not know the real questions and process JPMorgan, P&G, Nestlé, or NVIDIA use in Taiwan; Mocky has built-in banks for these foreign-company internships and management-trainee tracks.
• Post-interview structured summary: ChatGPT's critique has to be requested and its format varies each time; Mocky produces a structured summary automatically at the end for review and progress tracking.

Price: How Far Free Goes, and What Paid Buys

Both have free tiers; the difference is the price structure of the "full voice experience": ChatGPT is a US$20/month subscription, Mocky is NT$199 one-time.

ChatGPT's free tier does plenty of drafting and text Q&A, but using the most lifelike Advanced Voice for a whole session and locking an interviewer role with a Custom GPT requires Plus, a US$20/month auto-renewing subscription. Mocky.pro's free tier is permanent with unlimited messages, capped only to one new session per hour. Paid is NT$199 one-time (about US$6.5, 14-day access, not a subscription, no auto-renew, refundable within 14 days), unlocking low-latency high-quality voice, a lifelike real-time Voice Mode, and 1:1 AI Coach. For a candidate sprinting through a round of foreign-company interviews, a one-time pass usually beats a monthly fee.

The Best Answer: Use Both

The most efficient prep is not either/or, but ChatGPT for "think and write" and Mocky for "speak and drill."

In practice we recommend this: first use free ChatGPT to research the company, draft answers, polish wording, and outline STAR stories until you know what to say; then go to Mocky, upload the same CV/JD, and say those answers out loud in voice, over and over, letting the AI interviewer probe and force you to respond under pressure, then review with the transcript and structured summary. The first solves content, the second solves delivery. They complement rather than replace each other. Honestly, if you only need to rehearse a few questions on a zero budget, free ChatGPT alone (with an interviewer Custom GPT or a prompt) is a fine start.

FAQ

Q: Is free ChatGPT enough to practice an English interview? Enough to start. It is strong at researching companies, drafting answers, and polishing. But for steady voice practice, CV-tailored questions, and a post-interview summary, free ChatGPT stalls, and that is where Mocky.pro fills in.

Q: Is Mocky.pro trying to replace ChatGPT? No. We neither do nor could beat ChatGPT's breadth and drafting. We focus on the "drill your answers out loud" part and recommend using both together, not choosing one.

Q: How do ChatGPT Plus and Mocky Pro compare on price? ChatGPT Plus is a US$20/month subscription (auto-renews); Mocky Pro is NT$199 one-time (about US$6.5, 14 days, no auto-renew). For a short interview sprint, the one-time pass is usually cheaper.

Q: Which foreign-company question banks does Mocky have? Built-in banks for JPMorgan, P&G, Nestlé, NVIDIA and more foreign-company internships and management-trainee tracks, with each one's salary, interview process, and predicted questions. General ChatGPT has no such company-specific data.

To compare more purpose-built tools, see the complete comparison of six AI mock interview tools; and if you are torn between ChatGPT and Gemini for interview prep, see ChatGPT vs Gemini for Interview Prep.

Already wrote your answers with ChatGPT? Head to Mocky.pro, upload your CV and JD, and say them out loud until they are second nature.