Yes, when you re-upload a PGN file (with the same games), it will skip already existing games (in that database). A game is considered a duplicate if the following is true:

You played the same pieces (white/black).

The date is the same.

Name of your opponent is the same.

The position reached after 40 moves (or at the end of the game if reached earlier) is the same.

In case, all four criteria match, we skip the game as we believe it is already present in the databaase.

However, please note that you can have duplicate games across multiple databases.


You find the full timeline with more information on this project on the About page. The project is not open source right now, but there is a page with more technical details.


You can change your payment method in the subscription settings. Press “Update payment information” and then select the desired payment method.


You can manage your subscription at any time in your account subscription settings.

You have the options to:

Change: This will allow you to switch to another plan, allowing you to upgrade or downgrade. You can also switch your payment cycle (like monthly to yearly).

Cancel: When you cancel your plan, you will remain your status until the end of the billing cycle.

Update payment information: Here you can change your credit card or your payment method.

The page will also show you when the next payment will be processed and show all your past invoices at the bottom of the page.

To cancel your subscription click on Cancel right below your current payment information. Afterwards you will be asked again to confirm your decision. Pressing “Yes, cancel my subscription” will confirm your decision and stop future payments. You can cancel at any time without notice up until 24 hours before the payment is due as in this time frame the payment will be collected.

If you don’t like ChessMonitor, we are very sorry. We are continually working to improve the product for you. If you have any technical problems or questions, please contact us.


To upload games use the PGN database. You find a guide on how to create a PGN database in the ChessBase Support:

Saving Games in PGN (ChessBase Support)

Then export your existing game database into the PGN database and save it. Afterwards, you can upload the PGN file to ChessMonitor.


Open your account options.

If you have registered with email and password, you can simply select “Change email address” when clicking on your email to enter a new email address.

If you have registered via OAuth, you can either select one of the email addresses provided via OAuth or select “Enter email address manually” to enter a email address on your own.

Please make sure to confirm your email address after you’ve changed it by clicking on the link in the email we will send you.


Currently, we only have profiles of popular players and players who have created a profile on their won on ChessMonitor.

If you are on the Professional plan, you can also reach out to us and we will create profiles for other people, for example if you want to prepare for a tournament.


This is not possible for now (but will follow later).

For now, the uploaded PGN must contain your name in each game as otherwise the games without you will be skipped when uploading.


When you login, your account information will be downloaded. So, just login again, or add the same account again to your profile and the data of your profile will be updated. If you renamed your account (on Chess.com) it might take a few minutes in some cases until all games are added to your new account.


If you experience technical problems or see an error message, please contact us.

It would be great if you could copy the content of this page which contains technical information about your browser, time zone, etc. which might help us to understand the problem.


Feel free to contact us. In case you have ideas or general feedback, you can also go to our community on Discord or on reddit (r/chessmonitor) and share your thoughts there. You can also follow the development there and even post ideas or feature requests.


Click on "Remove Account" next to your profile name in the Account page to remove an account from your profile


In your account page, you can see how many other users are in front of you in the column on the right. On average it takes about 1 minute for each user. In some cases, users with tens of thousands of games are added which then takes a while to add... The first time your games are downloaded might therefore take between a few minutes and up to a day.


The data shown here is provided by the chess websites. If you don't want that data to be public you should remove it from your profile on the websites and then logout/login to update your profile information.

Alternatively, you can also go to your profile settings and enter a your public profile name. This will overwrite any value from chess websites.


All pages are cached to reduce the load on the database. If you visit different pages while your games are being downloaded, the results might differ. That said, the queue is cleared for you as soon as all games are downloaded and the pages will all show correct values.


Only normal chess games are downloaded, excluding any variants like Chess960. Also, bot games are excluded.


If you have just created your profile, give it some time. As the server needs to read all countries of all your opponents, this might take a few hours or even days when it's done for the first time. Just check back later.


Bookmarks are a way to remember often visited profiles.

Setting a bookmark

The most recent bookmarked profiles will appear at the top.

On your mobile device, it looks like this:

View on mobile devices {"style": "max-width: min(320px, 95%)" }

This functionality is only available to Plus and Professional users.


PGN databases (or user databases) are a way to upload your own games to ChessMonitor. After uploading games via PGNs, the uploaded games will appear next to your online games.

You can also filter statistics specific to an uploaded database by using the “Account” filter (on the explorer or games page).


When you add an account to your profile (or you login for the first time), ChessMonitor will start to download your games. Games are downloaded one after another. In case, another user is still waiting for his games, you are placed in a queue.


Basically the same as when you added your account. Your games will be downloaded. But this time, this will be a lot faster, as the algorithm can start from where it left meaning that it will skip all previously added games. While the first time your games are read is often rather slow, a simple update is often done in seconds.


OAuth (short for “Open Authorization”) lets you log in to websites or apps using your existing accounts from services like Google or Facebook, so you don't need to remember another password. It’s a secure and easy way to sign in with just a few clicks. When you use OAuth to login on ChessMonitor, your password is not shared with ChessMonitor.

Chess.com as well as Lichess do offer login via OAuth allowing users to add their accounts in a very simple way (assuming you are already logged in). You can even add multiple accounts by logging out of one of your Lichess accounts and then logging into another account.

As an alternative to OAuth, you can also register with email and password. If you are already signed into ChessMonitor, you can still add a password to your account allowing you to log in with your email and password in the future.


A queue is used to make sure all games are downloaded sooner or later. Most of the time, the queue is empty and by adding your account or clicking "Update" your games are immediatly downloaded. But in some cases, you might have to wait until your games are ready. You don't have to stay on ChessMonitor to keep your place in the queue. You can simply come back later.


We have a dedicated page for our tech stack that describes the technologies and software we are using. The page lists all libraries used by ChessMonitor.


Paddle.com is our payment provider. That means they also create the invoices and handle all payment related issues. For that reason you receive an invoice from Paddle.com and your credit card (or PayPal) statement will show Paddle on the receipt.

Your credit card (or PayPal) statement should show:

PADDLE.NET\* CHESSMONIT

It only shows CHESSMONIT (instead of CHESSMONITOR) as most banks and statement only allow a relatively short notice.

If you have any question related to your invoice or payments, feel free to reach out to us.


The Explorer and game opening detection work slightly differently. While the game opening detection considers the last known "opening position," the Explorer evaluates a sequence of moves. This can lead to differences in the displayed game counts. Although the output may vary, the underlying mechanisms aim to provide accurate information for your chess exploration.


ChessMonitor Knowledge Base

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