AnimeRG (Anime Release Group) version of Naruto Shippuden is a popular unofficial high-definition digital release, typically distributed in 720p or 1080p using modern codecs like x265 (HEVC)
Happy viewing, and believe it!
Now, whether you press play on Episode 001 or Episode 500, remember the words of the hero himself: "I never go back on my word, because that’s my nindo—my ninja way." animerg naruto shippuden complete series 001