Mods Tutorial

Make sure you disable any other extension and scripts first!

Play Menu:

Here you can enter your name and press play. You can also make a party by clicking create party and giving the code to your friends. They need to paste the party code you gave them and press join party. You will always join the creator of the party even if he switches server.
Graphics Menu:
You can change your graphics by clicking on the graphic quality tab. You can also choose a standard background by clicking on the background tab. If you want to have a custom background select the button choose file and choose your file. When you are done with that click set background and the background is done.

Connection Menu:

Here you can choose on which server you want to play. Your friend can give you the ip of the server he is playing on, so you can paste it and play on that specific server too.

Settings Menu:

Here you can choose your clan tag by filling in the “Clan tag” button. Underneath the clan tag, you can choose the name of the clan. The clan tag is the tag before your name and the clan name is how your clan is called. You can also change the clan logo by pressing the button change logo, that is with a url, or a file from your desktop. Choose a file with the size 200×150. You can choose a file the same way as you did with setting your custom background.

Help Menu:

Here you can see all the extra controls for this mod. There you can also find the link to this tutorial and how to delete or disable this extension.

Contact Menu:

Here you can contact the team of this mod or report a bug.

Respawn – ESC
Zoom In/Out = Mouse wheel scroll Down/Up  and i/o keys
Die – Q
Reset Zoom – Tilde/Grave (~/`) or Period (.)
Toggle HUD – TAB
Toggle Skin Rotator – W
Boost/Speed – Shift/Space/Left Mouse Button
Enable/Disable Bot (BETA) – F

  • Multi language (German, Turkish, English, Spanish, Dutch, French, Polish, Russian, Brazilian Portuguese, Finnish, Hebrew and Czech for now, if you want more added, don’t hesitate to contribute and we’ll add your name to the credits list!)


This post is intended to help the Google Chrome users on how to install or uninstall user script (or Google they call it Content Script) in their browser. Google Chrome rapid updates and changing had cause a lot of problems on how user can install user scripts and how the user script interact with the browser. To make thing simple, I’m going to introduce you all to Tampermonkey extension in Google Chrome which is very similar to Geasemonkey add-on in Firefox. Trust me, this will make your life easier.



Install Mods on Google Chrome


Step 1: Open Tampermonkey extension and install it. Once you have installed the extension, you should see a Tampermonkey icon button at the top right hand side corner near the Menu button in Google Chrome.1


Step 2: Go to Mods and find the Mods you want to install. For example, if you want to install Mods, open it and hit the install button.

install Mods


Step 3:  Done! Refresh the page if you want immediate effect from the script which you have just installed. If you wish to edit the script which you have installed. Click on the Tampermonkey icon button, go to Dashboard. Now you can see the list of user scripts which you have installed. You can select any one of them and start modify it anytime. Remember to save after done modification.





Install Mods on Firefox / Safari


Step 1: You need to make sure you have Greasemonkey extensions installed on Firefox. Tampermonkey for Safari


Step 2: Download the Mods from to install button. Mods Install


Step 3: Click on the Install when Greasemonkey prompt you to confirm install the script to Firefox.comfirm

Step 4: Done! Continue to read if you want to know how to edit the script.




Make sure you disable any other extension and scripts first!



How to Disable other Mods Scripts/Extension?



Disable/Delete other user scripts in chrome:


Step 1: Open the Tampermonkey Dashboard by clicking on the Tampermonkey icon button on the menu bar, then select Dashboard.



Step 2: You should see a list of user scripts which you have installed. Search for the user script you want to delete and click on the delete button.


Step 3: Confirm the delete by click on the OK button and you should see the user script is no longer on the Dashboard.

2016-05-19 19_14_55-Tampermonkey

Step 3: Done!





How to uninstall an Other Extension on Chrome?

Step 1: On your browser, click menu . Select More tools > Extensions.

2016-05-19 19_17_44-

Step 2: On the extension you want to remove, click Remove from Chrome . A notice to remove the extension will appear. Click Remove.




Step 3: A notice to remove the extension will appear. Click Remove.

If an extension has an icon in your Chrome toolbar, you can right-click on the icon and select Remove from Chrome to uninstall the extension.

To see your Chrome extensions, go to chrome://extensions. Here are a few ways to manage your extensions:




How to uninstall user script on Firefox:


Step 1: Go to Menu on top of Firefox then Tools > Greasemonkey > Manage User Scripts


Step 2: Select the script you want to edit and click Remove button.

2016-05-19 19_27_22-Add-ons Manager


Step 3: Done!


  1. Pingback: Mods User Script | Skins, Hacks, Mods, Unblocked | Slitherio - Slither io - - Slither Games

  2. Pingback: Mods Chrome Extension | Skins, Hacks, Mods, Unblocked | Slitherio - Slither io - - Slither Games

  3. I successfully installed it. But I have a question.
    Why every time I click left button on mouse to speed, the game freezes and when it’s back to normal I am already dead?
    I cleared my browser’s cache but nothing :/
    Is my laptop too old or what? It is 5 years old ”acer” and I don’t have windows 10 yet, is that a problem or something else?

  4. First time I ever used greasemonkey and tampermonkey. Never have installed any scripts ever before. this is the first time. History cache totally emptied from Firefox. Haven’t used Chrome on this computer until I installed it today to get the mod script working with SlitherIO. So very fresh installs of this mod.
    Script shows available in Firefox when the game is there, but the mod doesn’t do anything, just vanilla game.
    Chrome, tampermonkey shows nothing available when I go to play the game, just vanilla game.
    The advice given to many in the comments below simply don’t do anything. I’ve been at this for three days, taking my time step by step. The instructions are very clear, but simply do not work.

    • i just try it for you on a clear pc. to see what is wrong on first install. it is works good. if you can send us screen shot from your pc we can look for your problem.

    • Anonymous

      Thank you. What do you need screen shots of and how do I send them to you?

    • Anonymous

      Is there an email address I can send them as attachments?

    • Anonymous

      I have screen shots of GreaseMonkey with latest (and only) script for
      shots of version and options, shot of start screen on this site with script “active” (but you’ll see does nothing)
      How do I post the screen shots. This page won’t allow me to paste or attach them.
      Do you have an email address or webpage for such things?
      Looking forward to figuring this out.
      Thank you
      PS do I have to join up to something for this to work? I couldn’t find anything like that.

  5. I’ve downloaded the script, how do i open the game so that i can literally play the game?

    • if you make your install you just need to join script will be activate when you join game

  6. Nguyen Tuan Dung Reply

    How to use BOT? If I press F button, the snake will run around.
    And add Vietnamese pls!


    So… it seems I have deleted all extensions per the instructions and installed Tampermonkey correctly and I see the script listed in the Dashboard, but how do I actually play the game with the mods now? If I go to, it’s just the basic game with no zoom or skin choice or anything… what am I missing?

  8. everytime i press install script it wont let it install and it says invalid script header

  9. shyna wolf Reply

    i did delet all of slitherio mods but i still cant install it

  10. shyna wolf Reply

    uhh its showing a screen that is diforent then yours on the video it wont let me donlode it

  11. Invalid script header?
    why cant i instal it?
    i keeps on saying “invalid script header”

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