Side-by-side comparison · AI Assistants & LLMs
ChatGPT vs Duck.ai vs Z.ai
Everything that matters when choosing between them, in one place: our rating, what each can do, what they cost, and the trade-offs.
Comparing 3 tools, the maximum.
At a glance
Pick it if: Anyone who wants one general-purpose assistant that handles most everyday jobs.
Pick it if: Anyone who wants quick AI help without an account or a record of what they asked.
Pick it if: Developers who want a cheaper engine for Claude Code and similar tools, and anyone who wants free access to a top open model.
ChatGPT scores highest overall, but Duck.ai gives you more for your money. Which one is right comes down to what you value most.
Overview
| Attribute | ChatGPT | Duck.ai | Z.ai |
|---|---|---|---|
| In one line | OpenAI's all-rounder: chat, images, voice, web search and agents in one app. | DuckDuckGo's private AI chat: no account, no stored prompts, free to use. | Free chat with Zhipu's open GLM models, plus a cheap coding plan for Claude Code users. |
| Pricing model | Freemium | Freemium | Freemium |
| Starting price | $8/mo | $9.99/mo or $99.99/yr | $18/mo or $12.60/mo |
| Free plan | Yes | Yes | Yes |
| Works with Claude Code | No | No | No |
Rating breakdown
Our scores out of 5. The higher bar in each row is highlighted.
| Attribute | ChatGPT | Duck.ai | Z.ai |
|---|---|---|---|
| Overall rating | 4.3Winner | 4.0 | 3.5 |
| Ease of useHow quickly someone non-technical gets value from it. | 4.5 | 4.5 | 3.5 |
| FeaturesHow completely it covers its own job, and how well the pieces fit together. | 5.0 | 3.0 | 3.5 |
| Output qualityHow good the results are before you fix them. | 4.0 | 3.5 | 4.0 |
| Value for moneyWhat you get for the price, including the free plan. | 4.0 | 4.5 | 3.5 |
| Speed & reliabilityHow fast it is and how often it falls over. | 4.0 | 4.5 | 3.0 |
Feature comparison
A tick means it does this today. A dash means we haven't checked.
| Attribute | ChatGPT | Duck.ai | Z.ai |
|---|---|---|---|
| Access & platform | |||
| Free plan | Yes | Yes | Yes |
| Mobile app | Yes | Yes | No |
| Desktop app | Yes | Yes | No |
| Browser extension | Yes | Yes | No |
| API access | Yes | No | Yes |
| Teams & business | |||
| Team workspace | Yes | No | Yes |
| Enterprise plan or SSO | Yes | No | No |
| Connects to other apps | Yes | No | No |
| Open source or self-hosted | No | No | Yes |
| AI abilities | |||
| Works with your files | Yes | Yes | Yes |
| Understands images | Yes | Yes | Yes |
| Makes images | Yes | Yes | No |
| Makes video | No | No | No |
| Writes code | Yes | Yes | Yes |
| Runs agents or automations | Yes | No | Yes |
| Learns your brand or style | Yes | No | No |
| Works in many languages | Yes | Yes | Yes |
| Capabilities score | 15/ 17 | 9/ 17 | 9/ 17 |
Pricing
Plans as listed on each vendor's site when we last checked. Confirm before you buy.
| Attribute | ChatGPT | Duck.ai | Z.ai |
|---|---|---|---|
| Plans | Free Free Trying it out and everyday questions. | FreeOur pick Free Quick private questions with no sign-up. | Chat Free Anyone who wants to try GLM or use Agent mode. |
Go $8/mo Casual users who hit the free limits. | Plus $9.99/mo or $99.99/yr Regular users who also want a VPN. | Coding Plan LiteOur pick $18/mo or $12.60/mo billed yearly Developers trying GLM inside their coding tool. | |
PlusOur pick $20/mo Anyone using it most days for work. | Pro $19.99/mo or $199.99/yr People who want the top models privately. | Coding Plan Pro $80/mo or $56/mo billed yearly Daily agentic coding. | |
Pro From $100/mo Heavy users and people living in Codex. | Coding Plan Max $168/mo or $117.60/mo billed yearly Developers running agents for hours every day. | ||
Business See website Teams from 2 people up. | |||
| Which plan to pick | The free plan is now good enough to use properly, so stay on it until the image, voice or research limits annoy you. Plus is the sensible upgrade. Only look at Pro if you run Codex or deep research all day, and read the current tier details first: Pro 200 now comes with a smaller allowance than it did before 29 September. | Stay on Free unless you also want a VPN. Plus is good value if you'd pay for a VPN anyway. Pro is $19.99, the same as ChatGPT Plus or Claude Pro, so only pick it if anonymity matters more to you than features. | For chat, it's free. Developers should start with Coding Plan Lite and code off-peak, because usage between 2pm and 6pm Singapore time on weekdays costs more credits. Move to Pro only if you hit the weekly cap. |
Key features
| Attribute | ChatGPT | Duck.ai | Z.ai |
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Pros and cons
| Attribute | ChatGPT | Duck.ai | Z.ai |
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Who each one is for
| Attribute | ChatGPT | Duck.ai | Z.ai |
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Questions people ask
Which is better, ChatGPT, Duck.ai or Z.ai?
ChatGPT scores highest overall in our ratings (ChatGPT 4.3/5, Duck.ai 4.0/5 and Z.ai 3.5/5). ChatGPT is best for everyday questions and brainstorming and making and editing images in the chat. Duck.ai is best for quick private questions and Using AI without signing up. Z.ai is best for cheaper agentic coding in Claude Code or OpenCode and free chat with a top open model.
Which is cheaper, ChatGPT, Duck.ai or Z.ai?
ChatGPT: There's a free plan, and paid plans start at $8/mo. Duck.ai: There's a free plan, and paid plans start at $9.99/mo or $99.99/yr. Z.ai: There's a free plan, and paid plans start at $18/mo or $12.60/mo.
How we compare
Ratings are our own, from using each tool, across ease of use, features, output quality, value for money, speed & reliability.
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