Getting a notification when a website becomes online

Question

I am looking for a program, web browser extension or website service that can give me some notifications (e.g., email or pop-up) whenever a website isn't down anymore.

Any price, license, web browser and operating system is fine.

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Use case: I have to prepare some tax form through https://www.glaciertax.com/, and the website is currently down. I would like to receive a notification whenever it is back online.

I am aware of https://www.downnotifier.com however one can only set a notification when the website becomes off-line and not the contrary:

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I have crossposted the question at:

• https://redd.it/65jjh1
• http://qr.ae/T5E6aP

Answer 1

How about this:

A simple POSIX compliant shell script. I tested it with both GNU and busybox versions of wget and in bash and ash. It opens a connection every 10 seconds and exits when a connection is established. It informs the user that the website is up by displaying a message box using zenity framework.

Alternatively, instead of using zenity it could send an e-mail using sendmail, msmtp or something similar.

#!/usr/bin/env sh

# check-up.sh: continously check if website passed in $1 is up using
#              wget and inform user when it's up with zenity

if [ -z "$1" ]
  then
    printf "Pass website address as the first parameter\n"
    exit 1
fi

command -v zenity >/dev/null 2>&1 ||
    { printf "Please install zenity first\n"; exit 1;}

command -v wget >/dev/null 2>&1 ||
    { printf "Please install wget first\n"; exit 1;}

while true
do
    if wget -q -O - "$1" >/dev/null 2>&1
    then
        break
    fi
    sleep 10
done

zenity --info  --text="$1 is online"
exit 0

Answer 2

Uptimerobot - Their Pro Plan appears to be able to do this. I use their free service for monitoring prospective clients web hosting accounts as a sales tool later

Answer 3

This website (still in alpha, and not sure if it works all good) should give you a pop-up when a site comes back online:
http://alpha.itsback.at

It is also on GitHub here https://github.com/aardvarks/itsback.at