Sonic can run faster then the speed of light

Correction, SUPER Sonic can. Sonic can run faster than the speed of Sound.

However, the Flash can run fast enough to travel through time and dimensions.

No , super sonic flys first off ,and anyone who has ever played a sonic game knows sonic runs faster then the speed of light. Even without the light shoes which states he can run faster then light. He has in every game (almost anyways). He has run around planet earth in mere seconds before. Without the use of the chaos emeralds. He has also run through space and time before.

The flash can run around the earth in seconds too. I remember him doing it in the justice league cartoon.

Not saying he can't and not saying sonic would definitely win however it is not so clear cut as the flash would win.

Dude, you're talking to someone who has literally played EVERY Sonic game there is.
Regardless of how big of a fanboy I am, Flash is faster.
Sonic has only been stated to run at a regular faster than sound speed.

Okay Well by using the boost button you automatically shatter the sound barrier. Then if you use the lightdash you run faster then the speed of light. Simple as that however he has been noted to run as fast as the speed of light without the use of chaos emeralds before.