Hello Codeforces!
I have now created a brand-new frontend for the cheater database that has been circulating in your CF recent actions for the last 48 hours. So now, please do NOT DM me or Proof_by_QED or cry. Now, you can submit reports here
Just a reminder that reports:
MUST contain conclusive evidence (just linking their profile and saying "he cheated" is NOT enough) Cannot contain too many submissions (we are human after all, we don't have all the time in the world) MUST have usernames spelt correctly. Case sensitivity is not important.
Here it is: https://cf-cheater-database.vercel.app/
Note that the Chrome extension remains unchanged and still works.
UPDATE 26/06/2025
Hello Codeforces!
It's been amazing seeing you all contribute to this project — so thank you very much for doing so. I need to share some updates.
APPEALS — now, if you feel you have been wrongly labelled as a cheater, you can submit an appeal directly on the website. Therefore, do not spam the blog further, and use the website.
CHROME EXTENSION — some people have reported a bug with the chrome extension where it does not highlight all cheaters. This was a genuine coding mistake from me, due to which I have released a NEW VERSION of the chrome extension. Please redownload it from GitHub and reinstall if you downloaded the extension before today.
OUTAGES — some people reported outages — these are again the fault of the developers, and the issues have been fixed.
POLICY – Add ALL cheaters to the platform, no matter how they cheated. Submit concise reports with clear, conclusive evidence — full profiles will be ignored. If a report is declined, gather stronger proof before resubmitting; do not spam the same report multiple times. If you are submitting a report and see a skipped submission/contest, you can attach it, but the mere existence of a skipped contest does NOT constitute conclusive proof that the user is a cheater, especially because Codeforces marks all but the last AC submission as Skipped in Div 1 and 2 rounds.
Thank you again for all of the support, with your help, we are well past 1000 cheaters in the database and this number is quickly increasing.
Please note that: "he's a cheater, I saw him cheating." is NOT conclusive evidence. If you do not have conclusive evidence, do NOT submit reports.
If you really saw someone cheating,just take a photo of the cheating behavior instead.
remove me from the list please. It is ruining my codeforces programming journey. I love cp. Please remove from your database please. macaquedev macaquedev
wowee
wowee
wowee
wowee
wowee
Big thanks to macaquedev for making this thing.I have been using it for a while now, and it’s made spotting cheaters so much easier. I really hope active contributors like cry continue pushing to get them banned. It’s frustrating to still see repeat offenders in almost every round.Cf deserves to be a place where fairness and skill are what matter most.
dang orz
Good that you marked chromate00. Also mark also your other fellow cheater contest setter friends like wuhudsm, Psychotic_D and Friedrich.
For the case of Friedrich I am assuming you are referring to this. Given the code length such a coincidence is quite likely. I know him well enough that I would be very surprised if he cheated at all, especially in this weird way.
hope this de-escalate the cheating situation
Why do not show the evidence?
yeah, it would be much convincing if the evidence is visible by everyone, and it won't do much bad.
Nice, I see that arnabmanna has been added
So, please add his new cheating alt, Destroyer0069 as well
He's more like Undisputed Biggest Cheater of all time
Make a report on the frontend.
Wtf .... Without any proof don't do that type f**ing things
which extension do you use for the rating to appear like that
Codeforces Helper by Darelife
Edit: If Darelife is reading this comment, I just want to say that this is a very useful extension. All four features of the extension help me and I use it. Amazing work.
ok so when will the cheaters be banned
bhai remove me from this cheater data base at once, I have 0 skipped contests!!!
Doesn't mean you haven't cheated. Looking at your submissions, you suddenly switch from short variable names and using bits.stdc to using library names and longer variable names? Either you copied from someone, or you're using an LLM and trying to humanise it with comments.
I don't want to hear a single word from you ever again.
https://mirror.codeforces.com/contest/2110/submission/321114563
bhai ChatGPT does not write comments with no capitalization and bad grammar 😭 😭 Now you are just adding non-cheaters to your database why? 😭 😭 😭 😭 😭 😭
Good job, bro. But how will this be translated into action? I mean what will happen after reporting.
It's saying failed to submit a report when i am trying to submit
try again.
I want to report Manasvi but it doesn't let me. Here's the proof, https://mirror.codeforces.com/contest/2078/submission/309840609
Added, not sure why it doesn't work on your end, everything's perfect on mine
Nice, I don't need to login to report right
no you don't
It is showing failed to submit report, please try again
try again.
Excuse me, why do you mark me as cheater ?. I need a reason. Which contest ? Which submission ?
Why did you mark me as a cheater? Do you have any valid reasons? I accept that I have one skipped contest, but the person who reported me also has one. I also sent you messages, but you are ignoring them. I need valid proof, sir.
Can I know why have I been flagged as a cheater? The website doesn't allow me to see the own evidence against myself?
I cant submit idk why
but here is a cheater Ak.24 see her submission and just 5 contests and boom expert.
When you say "I can't submit", can you please send me screenshots of your console and what you see when you try to submit a report? It works perfectly on my end, so I'm not sure what's up with the fact that multiple people complain of the site not working on their end?
Error while trying to use the following icon from the Manifest: https://cf-cheater-database.vercel.app/logo192.png (Download error or resource isn't a valid image)
This error is patched, but it turns out there is a more serious issue with the database that I am now working on to fix.
Can you please try creating a new report?
There was an issue where people could not report, should be fixed now.
:(
Auto comment: topic has been updated by macaquedev (previous revision, new revision, compare).
Auto comment: topic has been updated by macaquedev (previous revision, new revision, compare).
hello, I am unable to submit appeal. I think someone has fraudulently submitted an appeal on my behalf and I cannot defend myself. Besides I am not a cheater, the allegations are false and submitted by someone who has a personal grudge against me. Please fix this at once sir!!!! img
How many times have people submitted a report that tourist is a cheater?
funnily enough, zero. The only reports for "tourist" have been my own, when I was testing the system haha
Counting macaquedev and me the answer is 2
these people be flagging anyone and everyone as cheater damn . Saw this guy flagged as cheater bro had 0 skipped contest all normal just one of the solution had comments which didnt seemed like written by gpt (had grammatical mistakes)
If you want to make an appeal, post the username on our website (not this blog). If not, stop yapping.
sussy amogus
How recent must be the cheating evidence?
all cheating is cheating.
I want to report SANDIPAN_KUNDU but don't know if the evidence is valid enough. Can someone confirm me? He is newbie getting more than 9000 rank everytime and can't even solve C but in last round he solves till D and gets 2000 rank. Takes 11 minutes on A and then solves C in 12 minutes. But took more than 1 hour on B and then solved D in 20 minutes. Is this suspicious enough for evidence macaquedev?
Another cheater from his cheating club is shubhu_279 who was consistent at 1650-1700 till October but rose from 1651 to 1890 in just 2 contests, solving Div 2E and getting Master perf all of a sudden even though he didn't practice much in that period. He is also very good in clearing plag so it is hard to catch him with code but his rating changes abruptly whenever GPT drops a new model. Is this evidence conclusive enough?
solving D in just 20 minutes is very fishy
But we can't say for sure
i have solved many d's in that time, it's not conclusive evidence.
Could you solve it as a newbie? Because jiangly can do all problems in 40 minutes doesn't mean everyone else can. Consider him being consistent newbie too. Is it good enough evidence then? And he also got a plag in cf round 1024.
please don't post here, just make reports on the site.
UPDATE: We received reports of fake appeals, so you now must verify that you are the owner of the account you wish to appeal.
neat, however is it possible to add image support? I had to use dropbox (or other third party) links which is rather annoying
secondly, for the chrome extension, could you do something similar to codechef in which it shows which contest is cheated directly on the rating graph and past contests table?
We don't currently store which contests were cheated
Regarding image support, no... unfortunately not because we're using a free plan of Firebase, and if we allow native image support our database will just reach the free plan limit way too quickly lol
Regarding showing cheating evidence, no, because then smart cheaters will learn to bypass detection.
wow
hello
Will the edge's extension update as chrome's ?
What was the point of all this when rollback didn't remove or unrate the AI-glorified cheaters?
Congratulations singhsoumya_coder Saar !!
I want to report fuad720 and tin.le2 they not leak code direclty but leak on cp helper website and they work like employee there and leak D E and also F problem sometime along with other top coder. Making people cheat is also cheating mark them too! they take money from cp helper founder per code. they are only employee but employee in cheating company is cheating!
Hello macaquedev, and to the moderators and community,
I'm posting here on behalf of my friend, Vivaan_Saraswat, because he has no other options.
His situation is severe: he has been TOTALLY BANNED from Codeforces. This isn't just an account ban; he cannot access the site at all from his main browser profile. This happened without any warning, no email, and no explanation. He strongly suspects his account was mistakenly flagged by anti-bot defenses.
To be clear: I am his colleague, and this is my own account. He has not created a new account and is respecting the single-account policy. He is not trying to evade a ban, but he has no other way to ask for a review. He has prepared a detailed appeal below.
[Start of Vivaan_Saraswat's Message]
Dear Codeforces Administration and Community,
I am writing to formally appeal my permanent ban. I believe this is a misunderstanding, and I hope to clarify any points that may have led to this decision.
Performance Variance & My 81-Day Streak: I acknowledge there can be a difference between my performance in contests and my regular problem-solving record. This is because I am far more focused and "locked in" during contests. This difference arises because I treat official and virtual contests with maximum seriousness. In contrast, many of my daily practice solves were done primarily to maintain my 81-day streak, because I believe consistency is key to learning. In my humble opinion, the dedication required for this is inconsistent with the mindset of a cheater who would simply copy-paste solutions. My performance in virtual contests is also consistent with my real contest performance, which I believe further demonstrates this point.
Full Transparency on AI: I do not use AI to generate solutions for problems on Codeforces. For full transparency, you can review my public repository at Github. The only instance of AI-generated content for a Codeforces problem is a single file in the "AAAA review" section. Outside of this single instance, I do not use AI to solve problems on Codeforces.
Verifiable Proof of Skill: As external proof of my abilities, my performance in the Science Olympiad Foundation's International Computer Science Olympiad (SOF ICSO) earned me International Rank 48, a Gold Medal of Distinction, a Certificate of Distinction, and a Certificate of Zonal Excellence. This can be verified at the results portal using my roll number: UP1903-10-C-020.
Detailed Comments: My submissions often have detailed comments because of my learning method. I use the Feynman technique, which is the process of explaining a concept in simple terms to solidify one's own understanding. This is how I approach (almost) every single problem, no matter whether it is in a real contest, a virtual contest, or just a random problem from the problemset. It is a personal learning exercise. I want to state for the record that while my learning process is thorough, I have NEVER AND WILL NEVER leak any code, explanation, strategy, or anything while or before a contest.
Redundant Libraries: I sometimes include both <bits/stdc++.h> and specific headers. This is a deliberate personal exercise to practice remembering all the necessary libraries in case I'm in an environment like Visual Studio where the bits header isn't supported.
I hope this detailed explanation clarifies that my actions were not malicious. I am committed to being a positive and rule-abiding member of the community.
Thank you for your time and for reconsidering my case.
Sincerely, Vivaan Saraswat (Vivaan_Saraswat) vivaansaraswat713@gmail.com
[End of Vivaan_Saraswat's Message]
Thank you again for your time and for the work you do for the community. We hope a moderator can look into this.
Yeah. Just shut up and stop bothering us.
https://mirror.codeforces.com/contest/2123/submission/326925776
macaquedev is not a codeforces admin and can do nothing to help you. With that being said, the submissions look very much like GPT generated code: 324793955
Thanks a lot for the specific information. Let me be clear, I do not represent Vivaan's views in any way and am just acting as a mediator since he has no access to the site, I do think that he is quite good but am in no way defending him with that. I will convey this message to him and will try to do my best to allow both sides to communicate, I owe him a favour or two (actually 5) and it is my moral responsibility to help provide justice, weather in favour of or against my friend's personal views while staying unbiased (this is basically me saying "please do not ban me, im not a cheater and I don't hate people" if I decide to shift here from my main atcoder profile{Im worse than a dolphin there}). I belive that justice is the soul force that can ....... wait, at this rate I will probably start a revolution to create a new country by the end of the month, that is all I had to say. Have a great day!
It would be much helpful if I could see the evidence or at least request for it. Is there any way that I can request evidence from the administrators.
Sir, I have a small doubt. I see in many contest results that many indian participants who give contests are getting marked as cheaters. Why it is happening sir? Is it because more indians give contests or there is some other reason? I just want to understand how this process is working and how fairness is keeped. Thank you sir.
This is an unfortunate well-established trend (since even before llms) that a disproportionate number of participants in India cheat in cf contests. One possible reason for this trend is the economic pressure in the region to have a high cf rating to get an interview/job is not as strong in other parts of the world.
UPDATE: I've been DDoSed. I have temporarily taken the website down, so please don't try to submit reports.
Are we allowed to use codes from articles available online?If yes, then why I am marked as a cheater.
They are allowed as long as they were published before the contest. You can appeal if you think you were wrongly marked
Yes it was published before the contest hopefully they remove the cheater tag
There are users that are marked as cheaters in the database but not yet banned. After how much time do they get banned.(if there is a specific timeline)macaquedev
Unfortunately, as I've said before multiple times, I do not have control over banning users — my database is unofficial and unaffiliated with the Codeforces organisation.
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Hi, I've been sent DMs about your case by 2 different users and now you're also writing comments on a blog.
If you truly didn't cheat, can you explain why you had different formatting in all your submissions in contest 2148? Seems like very clear evidence for plagiarism... and the fact that all your submissions got skipped suggests that Codeforces also picked up on the plagiarism.
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Problem D: https://mirror.codeforces.com/contest/2148/submission/338464774
#include<bits/stdc++.h>(no space)void solve()(the { is on the next line)Problem C: https://mirror.codeforces.com/contest/2148/submission/338439657
#include <bits/stdc++.h>(with space)void solve() {(no newline)... that's pretty clear evidence. But if that's not enough, let's look further within the same contest.
Problem C: https://mirror.codeforces.com/contest/2148/submission/338439657
cin >> n >> m;(with spaces)Problem B: https://mirror.codeforces.com/contest/2148/submission/338406086
cin>>n>>m>>x>>y;(no spaces)Of course, it is possible that this is because you accidentally triggered some sort of automatic code formatter in your IDE on problem C. However, this cannot be the case, because of the following:
Problem C: https://mirror.codeforces.com/contest/2148/submission/338439657
cin >>arr[i].first >>arr[i].second;Note irregular spacing around the
>>operators...So yeah, unless you give me a good explanation on how on earth that happened, I'm not removing you from the database. Usually, I completely ignore skipped contests whenever I am trying to determine whether someone should be in the DB or not, but in this particular case, the fact that I've been able to find all of the evidence, and also that you have been caught not once but twice, I find it extremely unlikely that both skipped contests plus what I said are false positives.
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