AI tools have gone from being a novelty to something millions of people now use for work, study, and everyday tasks – whether it is writing an email, checking a piece of code, creating an image, or searching for information.
But convenience can quickly turn into frustration when a tool stops responding, runs slowly, or simply does not work as expected. Reddit has become one of the places users go to vent about those problems, compare experiences, and find out whether others are dealing with the same issue.
A new study by Go Humanize AI has analysed 20 popular AI tools to find which ones attract the most frustration-related discussion on Reddit.
The study looked at 20 popular AI tools and analysed Reddit mentions containing six terms linked to frustration: “error”; “not working”; “broken”; “annoying”; “slow”; and “frustrating”. The mentions were combined for each tool before the platforms were ranked from highest to lowest.
The study measures frustration-related discussion rather than each tool’s quality, so bigger, more widely used platforms may naturally appear more often.
Results of the study show
ChatGPT ranks first, with 42,15-million combined mentions. “Not working” is the biggest complaint at 22,6-million mentions, followed by “error” at 10,5-million, and “broken” at 2,8-million. As one of the most widely used tools in the study, ChatGPT is used for writing, research, coding and other everyday tasks, giving users plenty to complain about when something goes wrong.
Character.AI comes second with 22,44-million mentions. “Annoying” is its biggest frustration-related term at 9,28-million, followed by “broken” at 6,41-million, and “slow” at 5,59-million. The platform is built around conversations with AI characters, so slow or inconsistent responses can quickly affect the experience.
Claude ranks third with 9,77-million mentions, with “not working” accounting for 8,63-million of them. Claude is often used for writing, research, and coding, meaning technical problems can interrupt users in the middle of longer tasks.
Gemini takes fourth place with 5,27-million mentions. “Not working” again leads the complaints, with 4,6-million mentions. The tool is used across a range of Google services, making reliability particularly noticeable for people using it during everyday tasks.
Notion ranks fifth with 1,03-million mentions. “Not working” leads at 626 000, followed by “broken” at 108 000, and “frustrating” at 83 500. As a productivity tool, problems can be especially annoying when users rely on it for notes, projects and work.
Grok places sixth with 803 400 mentions. While far below the tools at the top, it still records a large amount of frustration-related discussion on Reddit.
Cursor ranks seventh with 658 200 mentions. The coding tool is designed to speed up development work, so errors or interruptions can quickly slow users down.
DeepSeek takes eighth place with 513 900 mentions, with Reddit users discussing everything from things not working to the platform being slow.
Microsoft Copilot ranks ninth with 480 200 mentions. Because it is built into a number of Microsoft products, problems can interrupt tasks people are already carrying out at work.
Perplexity rounds out the top 10 with 312 600 mentions. As a tool used mainly for search and research, users tend to expect quick and reliable answers.
At the other end of the ranking, complaint levels fall sharply.
Grammarly ranks 18th with 92 600 mentions, while Runway takes 19th with 35 380.
QuillBot ranks 20th with 16 920 mentions, the lowest figure in the study.
Overall, the results show a wide gap between the biggest platforms and those lower down the ranking. ChatGPT records almost twice as many frustration-related mentions as Character.AI, while “not working” is the most common complaint linked to several of the biggest tools.
The full ranking:
| Rank | AI Tool | Error | Not working | Broken | Slow | Annoying | Frustrating | |
| 1 | ChatGPT | 42,146,000 | 10,500,000 | 22,600,000 | 2,800,000 | 4,980,000 | 688,000 | 578,000 |
| 2 | Character.AI | 22,437,000 | 613,000 | 172,000 | 6,410,000 | 5,590,000 | 9,280,000 | 372,000 |
| 3 | Claude | 9,771,200 | 389,000 | 8,630,000 | 341,000 | 210,000 | 126,000 | 75,200 |
| 4 | Gemini | 5,274,900 | 233,000 | 4,600,000 | 130,000 | 150,000 | 104,000 | 57,900 |
| 5 | Notion | 1,030,300 | 67,800 | 626,000 | 108,000 | 79,400 | 65,600 | 83,500 |
| 6 | Grok | 803,400 | 108,000 | 346,000 | 108,000 | 117,000 | 65,700 | 58,700 |
| 7 | Cursor | 658,200 | 92,900 | 349,000 | 52,800 | 67,400 | 49,400 | 46,700 |
| 8 | DeepSeek | 513,900 | 106,000 | 209,000 | 51,300 | 82,000 | 35,600 | 30,000 |
| 9 | Microsoft Copilot | 480,200 | 91,500 | 268,000 | 31,800 | 34,400 | 27,700 | 26,800 |
| 10 | Perplexity | 312,600 | 59,400 | 137,000 | 31,400 | 37,800 | 23,000 | 24,000 |
| 11 | Canva | 308,600 | 18,700 | 156,000 | 12,400 | 16,700 | 48,600 | 56,200 |
| 12 | Suno | 270,600 | 29,800 | 87,800 | 32,000 | 55,100 | 31,800 | 34,100 |
| 13 | JanitorAI | 169,450 | 20,600 | 99,100 | 12,100 | 14,500 | 16,900 | 6,250 |
| 14 | DeepL | 162,990 | 15,000 | 93,300 | 11,700 | 14,500 | 8,290 | 20,200 |
| 15 | Replit | 162,860 | 28,700 | 92,600 | 12,500 | 12,900 | 7,070 | 9,090 |
| 16 | ElevenLabs | 158,180 | 20,500 | 98,900 | 10,100 | 13,400 | 8,790 | 6,490 |
| 17 | Poe | 92,960 | 4,610 | 79,100 | 2,820 | 2,990 | 1,810 | 1,630 |
| 18 | Grammarly | 92,600 | 10,200 | 55,500 | 5,530 | 6,040 | 7,040 | 8,290 |
| 19 | Runway | 35,380 | 3,430 | 24,000 | 2,260 | 2,810 | 1,580 | 1,300 |
| 20 | QuillBot | 16,920 | 2,290 | 10,200 | 1000 | 1,250 | 1,090 | 1,090 |
Source: Reddit