Auth Token Questions - Blynk IoT

I am having trouble migrating to Blynk 2.0. I have been using Blynk Legacy for 4 years and had no trouble at all. Now I need to migrate to 2.0 and I’m having all kinds of problems- mainly with the auth token. Some people said that the auth token is related to the Legacy app but I am still being asked to enter it and the one I enter is always wrong. I am using an ESP8266 and when I go to its hotspot I must enter an auth token or it will not proceed. Most of the time I do not have an auth token. Does Blynk 2.0 require one or what ?

At one point I had a basic communication from a sensor on the ESP to a gauge on the web dashboard working. But it did not work on the mobile app - the device was not in the list so I could not select it. I fiddled with some settings and then everything broke and I could no longer enter credentials into the board’s hotspot.

Also- I couldn’t see how to post to a topic- here I am replying to your message- I couldn’t see how to post a new message to the topic.


The advantage of creating a new topic, and selecting the “Need help with my project” category is that it prompts you to provide some basic information, which is helpful to us.

As you haven’t done that’ I’ll ask for some of it here:

  1. What Blynk library version are you using?
  2. Exactly what hardware are you using?
  3. What sketch are you using? When you post your sketch to the forum please put triple backticks, on a line of their own, at the beginning and end of your sketch.
    Triple backticks look like this:
    Please copy and past them if necessary

I would also suggest that you post your serial output. When you do this please dont post screenshots. Instead copy the text from your serial monitor ad paste it here, but once again, add triple backticks so that it displays correctly.

Information about what you’ve done regarding the creation of templates, and devices based on those templates would also be useful.


Hi Pete,
I have successfully connected three devices using three templates to Blynk 2.0.

I have two ESP32 devices and one ESP8266. Two of the devices send temperature readings to gauges and graphs and one device sends two time values (string) to labels and float values once a week to a bar graph.

I have several questions:

  1. Is Blynk 2.0 still a work in progress? I am asking this because of the next questions below:

  2. Can I change a device name and still keep the same auth code? I would like to change the name so I can change the order in the dashboard.

  3. Will the background colors be able to be changed in the future for both the web dashboard and the mobile app?

  4. I tried to download the graph data but didn’t get anything except some time values and online / offline status. I would like to download the graph data, which is temperature values every ten minutes.

  5. I duplicated the “Quickstart Template” to create a new template. When I deleted widgets from the duplicate copy those same widgets disappeared from the original template. Is this normal and why?

Of course, it’s a constantly evolving platform and will continue to be improved over time.

Yes. you can rename the devices without having an effect on the auth token.

Web dashboard allows a light and dark theme at the moment. I believe that a dark theme is in the pipeline for the app, and may already be available for Android.
I have no idea if custom themes will be available un future.

What subscription type do you have?
If it’s not Basic/Free then you may need to enable raw data for datastream, but TBH it’s impossible to say based on the info you’ve provided.

I don’t know. Personally I try to steer clear of the QuickStart template and also of duplicating templates. It does sound like a bug, but you’d probably be best creating a new Issues and Errors topic with full details, screenshots etc.


Hi Pete,

Thanks for being patient with me.
I was able to rename one device without having to change the code- thanks for help on that.

I have the Plus subscription. It allows up to 10 devices and I currently have three.

I don’t see where the color in the Web dashboard can be changed. Please advise

New problem: On one of my devices I have a super chart with three data streams (three curves). I can only download a report for one of them- when I try the other two it says “No data to download”. But the graph shows all three data sets. I tried setting “Raw”, “1 Minute”, etc. but I got the same results.
I originally downloaded all and got all the data but it was interleaved so I wanted to get individual data sets and that’s when I had trouble.

Thanks for your help.