Interesting websites for pronunciation practice
This page used some information from Sunburst Media's Pronunciation Web Resources, a very comprehensive list at https://www.sunburstmedia.com/PronWeb.html, as a basis for this much shorter list. The goal is to focus on sites that are good and easy for students to use.
Very interesting, but you need a relatively fast connection
  Okanaga's English Pronunciation at
      
  https://international.ouc.bc.ca/pronunciation/
   has a series of activities. Start with the introduction, then try the
  tongue twisters and dictation exercises. It works on th sounds, l and r, long e and short i, s/sh/ch, j and zh,
  v and w, and short a and short e. 
  
  
Diphthong Calculator by Steve Chadwick is at https://www.stuff.co.uk/calcul_nd.htm. 
      This lets you put
      vowel sounds together to end up with a dipthong.
   
   
Okay for people with modest speed
 The American Speechsounds website has some 
  free activities, as well as support for SpeechCom software and  online help for language learners. Some help is free,
  but more detailed advice is available for a fee. 
  
  Adam Rado's English Learning Fun Center is a commercial site, but you
  can try some pronunciation activities at https://www.elfs.com/MMz.html 
  for free. To get more, you need to sign up for a free subscription.
  
  
  You can sing along with Online Karaoke at https://www.karaokeplay.com/. This requires 
  a free registration. You can save your singing and have it rated by others online - a little competition and interaction. 
  
  Charles Kelly's American English Pronunciation Practice has a number of minimal pairs and other practice lessons 
  at https://www.manythings.org/pp/. They 
  require Flash v4 or higher to run. Students will need to select the 
  appropriate lesson from the list. Included are practice lessons  minimal pairs, using mp3 files, as    
      well as tongue twisters and a couple of songs.
       
  
  Eva Easton offers a number of interesting pronunciation exercises at 
  https://evaeaston.com/.
  They require the RealAudio player. Try 
  these to start:
Consonants
Vowels
Greetings - reduction
Linking
Reduction
Stress patterns
Okay for anyone - text files
English Club at https://www.englishclub.com/pronunciation/index.htm has explanations in simple language for many pronunciation issues.Tongue Twisters
All of these give you lots of phrases to try to say. Work with a
    friend or a pronunciation assistant! Try the 1st International Collection
    of Tongue Twisters by Michael Reck at 
      https://www.uebersetzung.at/twister/en.htm for more tongue twisters
    than you ever wanted. See if there are some twisters in your own language,
    too, at 
      https://www.uebersetzung.at/twister/index.htm
  
  
    Find more tongue twisters and information about alliteration at https://www.eslpartyland.com/articles/tongue-twisters.html
The English Pronunciation Test at https://pauillac.inria.fr/~xleroy/stuff/english-pronunciation.html will drive you crazy if you work on it too long. Use it little by little, and try to see the joke!
For Teachers:
David Dalton's ITESL-J article, Some 
    Techniques for Teaching Pronunciation, offers classroom activities 
    for 
  teaching pronunciation.
  
  Deborah's 12-Step  Pronunciation Program - a nod to the masters of psychology and self-help.
