As Congress meets on Wednesday to certify Joseph R. Biden Jr.’s victory in the November election, President Trump and his supporters continue to spread rumors, conspiracy theories and misinformation about the vote.

Here are six false voter fraud claims that may be repeated during the proceedings on Wednesday.

No, ‘glitches’ in Dominion Voting Machines did not change vote tallies.

Claim: Dominion Voting Systems, which makes software that local governments around the nation use to help run their elections, deleted votes for President Trump.

Fact: There is no evidence that any voting system deleted or lost votes, including the machines with Dominion software, according to the federal agency that oversees election security.

Background: In the weeks after the election, President Trump and his supporters spread baseless claims about Dominion. The claims included theories that “software glitches” changed vote tallies in several states, including Michigan and Georgia. No such changes were ever found.

Mr. Trump and his supporters subsequently claimed that Dominion had hidden evidence of voter fraud, both by destroying machines or removing parts within the machines. Mr. Trump repeated those claims during a call with Georgia’s secretary of state last weekend. Gabriel Sterling, a top election official in Georgia, said Monday of the claims of election fraud in the state, “This is all easily, provably false.”

No, politicians in Georgia did not prevent an analysis of absentee ballots.

Claim: President Trump and his supporters have claimed that absentee ballots in Georgia were rife with fraud and that state officials have not fully investigated.

Fact: Election officials have audited absentee ballots and found “no fraudulent absentee ballots.”

Background: The Georgia secretary of state, Brad Raffensperger, a Republican, ordered law enforcement and election investigators to conduct an audit of more than 15,000 absentee ballot envelopes in Cobb County, based on a complaint that signatures were not adequately checked there. The audit found no fraud. Mr. Raffensperger has said that he also plans a statewide audit of each county’s signature-match policies and procedures.

Georgia has already conducted two recounts, both by hand and machine, of all five million ballots cast in the state. No voting fraud was found.

No, thousands of votes in Arizona were not changed to favor Biden.

Claim: In an interview on the conservative cable channel Newsmax in December, the Arizona Republican chairwoman, Kelli Ward, said 200,000 ballots were digitally changed to give the victory to Mr. Biden, and Representative Paul Gosar amplified the falsehood on Twitter.

Fact: Audits in Arizona have found no evidence of voter fraud, or changed vote tallies.

Background: While early results in Arizona showed a close race, the final count revealed that Mr. Biden had won the state by more than 10,000 votes.

Audits in Arizona’s four largest counties, which make up 86 percent of all votes in the state, turned up no evidence of systematic voter fraud.

No, election workers didn’t stuff fraudulent ballots into suitcases.

Claim: President Trump’s supporters have pointed to a video as proof that ballots were pulled from a “suitcase” at a vote-counting center in Atlanta.

Fact: Election officials have said the surveillance video shows normal ballot processing. It is not unusual practice for poll workers to store ballots that still need to be counted on-site at the polling center.

Background: As reported by The New York Times, late on Nov. 3, election workers in Fulton County, Ga., heard that they would be allowed to stop the vote-counting and retire for the evening. So they packed uncounted ballots into suitcases and prepared to lock up. When word came that they couldn’t leave yet, they dragged the suitcases back out and began counting the ballots again.

But that scene of election workers taking out suitcases of ballots was selectively edited and pushed by allies of President Trump as one of the many false theories purportedly proving widespread election fraud. The conspiracists also named the election worker Ruby Freeman as a specific player in this false conspiracy event.

No, there isn’t evidence that Pennsylvania election officials violated state law.

Claim: President Trump’s campaign has claimed that Pennsylvania election officials improperly handled tens of thousands of mail-in ballots in violation of state election law.

Fact: The Trump campaign’s legal efforts to disqualify votes in Pennsylvania have been unsupported by evidence.

Background: The Trump campaign filed several claims in court seeking to invalidate Pennsylvania’s election results, and one ally of Mr. Trump, Senator Josh Hawley, has said he would challenge the results because he believed “some states, particularly Pennsylvania, failed to follow their own state election laws.”

But the Trump campaign has included no evidence that any vote had been cast illegally.

In a hearing on Nov. 17, President Trump’s personal lawyer, Rudolph W. Giuliani, acknowledged he had no proof to back up his claims of voter fraud in Pennsylvania. “This is not a fraud case,” Mr. Giuliani said.

Four days later, the judge overseeing the case dismissed the lawsuit. It was also shot down last month by Judge Stephanos Bibas, a Trump appointee to the U.S. Court of Appeals for the Third Circuit, who said in a ruling, “Calling an election unfair does not make it so. Charges require specific allegations and then proof. We have neither here.”

No, Pence does not have the power to change the election result.

Claim: Vice President Mike Pence can reject state electors in the Electoral College.

Fact: Federal law stipulates that the vice president’s role is to count Electoral College votes, not decide whether they are valid.

Background: President Trump on Tuesday falsely claimed on Twitter that Mr. Pence has the power to reject electors when the Electoral College vote is certified.

As president of the Senate, Mr. Pence is expected to preside over the pro forma certification of the Electoral College vote count in front of a joint session of Congress. The only electoral certifications available for Vice President Pence to preside over are the ones approved by each state.

Ben Decker and Jacob Silver contributed research.