Jack Beasley travelled from Durham to take part in the protest which brought Walsall town centre to a standstill on September 29 last year.
Miss Rhiannon Jones, prosecuting, told yesterday's hearing at Walsall Magistrates Court that the 23-year-old also allegedly threw a 'missile' towards police.
She said Beasley was seen on CCTV pointing aggressively at police and swearing.
Miss Jones said footage also showed him picking up materials from the floor near a pub, including a piece of wood.
She told the court: "There are two photographs of the defendant apparently throwing an object at what would be towards police lines."
Beasley was arrested at the scene and made no comments during interviews.
Miss Jones said he was a member of the South Shields EDL division.
Beasley, of Cedar Road, Bishop Auckland, initially denied used threatening words or behaviour with the intent to cause fear or provoke unlawful violence, but changed his plea to guilty on the day of his trial.
When asked whether he threw anything at police, he said: "I didn't throw no missiles."
District Judge Michael Morris adjourned the hearing for a pre-sentence report to be prepared.
He told Beasley: "Your level of violence was such that I need to consider all sentencing options, including a prison sentence.
"I'm also considering making a criminal anti-social behaviour order."
The case was adjourned until July 9 and Beasley was released on conditional bail.
In September last year, trouble flared at the rally in Leicester Street, while Unite Against Fascism held a separate event elsewhere in the town centre.