DreamHost had argued the DoJ's warrant would have revealed 1.3 million IP addresses.
The DoJ has now narrowed the scope of its demand.
Disruptj20.org was set up to help arrange a protest at President Trump's inauguration.
"The government has no interest in records relating to the 1.3 million IP addresses that are mentioned in DreamHost's numerous press releases and opposition briefs," prosecutors said in the new request.
They were focused on the use of the website to plan and carry out a criminal act - a "riot" - not the "lawful activities of peaceful protesters", they said.
The warrant does not now require certain access and error logs, which, DreamHost says, means visitors' IP addresses are "largely safe".
"We see this as a huge win for internet privacy, and we absolutely appreciate the DoJ's willingness to look at and reconsider both the scope and the depth of their original request for records," DreamHost said in a blog post.
However, it still plans to challenge the DoJ on other aspects of its request.
Prosecutors signed the original warrant to DreamHost in July, arguing that disruptj20.org had been used to organise "violent" protests in Washington DC.
DreamHost and privacy advocates argued that amounted to a "digital dragnet".
In its updated warrant, the DoJ said that the full scope of the original request - criticised by DreamHost in its public statements - had been "unknown to the government and the court at the time that the warrant was issued".
Data still required by the amended warrant includes files and databases stored by DreamHost.
More than 200 people have been charged in relation to rioting at the inauguration.

The protesters stormed the Congress and set fire to the building.
The authorities have arrested four police officers after a protester, Rodrigo Quintana, was killed.
Political leaders on Saturday paid their respects to the dead man.
His body was laid out at the headquarters of the opposition Liberal party in the capital, Asuncion.
They condemned the killing and called for an investigation into his death.
Around 200 protesters were detained but many have since been released.
The protesters had taken to the streets following a private meeting of 25 senators - a slight majority of the house - which approved a bill to amend the constitution.
Paraguay was controlled by military ruler General Alfredo Stroessner, who seized power in a coup, from 1954 until 1989.
The current constitution, created in 1992 after the dictatorship, limits the head of state to a single five-year term.
Protesters were angered by the bill which would have allowed President Cartes' to remove the restriction and run for re-election.
An opposition senator, Desiree Masi, called the move a coup and called on supporters to resist it.
The bill must also be approved by the other house of parliament - the chamber of deputies - where President Cartes' party holds a majority.
President Cartes' term is due to end in 2018.

The 37-year-old was detained following a joint investigation between Lancashire Police and the RSPCA.
A member of the public filmed the dog being punched at about 15:15 GMT on 10 December in Hendon Road, Nelson.
The RSPCA said the dog - an adult female Staffordshire Bull Terrier cross - has been checked over by a vet and is now in the charity's care.
RSPCA Inspector Charlotte Booker thanked people for their response to an appeal and said: "It has been absolutely huge over the last 48 hours and we are very grateful for the scale and quality of this response.
"The same name came forward various times so we were able to verify information quickly. I'd also like to thank Lancashire Police for their help in this joint operation."
Visitors to an anti-Trump website will probably not have their internet protocol addresses turned over to the Department of Justice, after a legal standoff with a US web company.
[NEXT_CONCEPT]
Paraguay's President Horacio Cartes has sacked the interior minister and the chief of police after violent protests on Friday against a bill that would allow the president to run for a second term in office.
[NEXT_CONCEPT]
A man has been arrested on suspicion of animal cruelty after a dog was attacked on a Lancashire street.