Spending on Cyber Monday, the biggest U.S. online shopping day, may hit a record $11.6 billion according to one preliminary estimate, as discounts on everything from pajamas to AirPods tempt shoppers to click "buy" despite the strain on household budgets from high inflation.

The estimate from Adobe Analytics predicts an increase of up to 8.5% from a year earlier. Much of the increase could be put down to inflation, which rose 7.7% in October, the lowest since January.

"If you exclude inflation, which has been running in high-single-digits, you come to a flattish number in real terms which would really not be too bad," Telsey Advisory Group analyst Joseph Feldman said.

Adobe Analytics measures e-commerce performance by analyzing purchases at 85% of the top 100 internet retailers in the United States. Both Adobe and MasterCard Spending Pulse are expected to release their updated Cyber Monday spending estimates on Tuesday.

Americans have put off holiday shopping for weeks in the hopes of finding deeper post-Thanksgiving markdowns. Retailers have dangled deals and discounts since as early as October to tempt shoppers to open their wallets.

"Shoppers are waiting out the season in anticipation of deeper discounts and are less susceptible to shiny objects," said Carol Spieckerman, president at consultancy Spieckerman Retail.

Target.com on Monday advertised discounts of up to 40% on Hot Wheels toys and holiday decor, while Amazon.com pitched 60% off promos on high-end watches and accessories.

Walmart's and Best Buy's websites also slashed prices by hundreds of dollars on some laptops and televisions.

Overall, shoppers found discounts of as much as 27% off listed prices on computers, Adobe said, and double-digit discounts on nearly all other categories, including apparel, toys and furniture.

With inflation running at multi-decade highs, consumers will still have to shell out more for popular products because prices have risen faster than promotions in many categories, according to data provided by DataWeave.

For the five days from Thanksgiving through Cyber Monday - one of the busiest shopping periods during the holiday season - Adobe estimates online spending will rise 2.8% to $34.8 billion.

This comes after brick-and-mortar stores and malls saw thinner crowds than usual on Black Friday due to inclement weather in some parts of the country.

Last year, Cyber Monday sales fell 1.4%, according to Adobe Analytics, as retailers kicked off holiday promotions early to avoid product shortages amid a global shipping crisis.

(Reporting by Uday Sampath and Ananya Mariam Rajesh in Bengaluru and Siddharth Cavale in New York; Editing by Anil D'Silva and Stephen Coates)