Looks similar to wisesheets.io , and wisesheets has mixed reviews. It might work for some use cases, but might not include all stocks, will have some number of data errors, and might be slow in updating after filings. Both wisesheets and SheetsFinance use XBRL data. Starting in 2021, all U.S. public companies were required by the SEC to file financial reports using XBRL. But XBRL data has some mistakes.

wisesheets says its data "is obtained from the company's financial reports. Each statement is standardized according to the XBRL US GAAP Taxonomy Preparers Guide."

SheetsFinance says "We are constantly reviewing and improving our global data delivery network. We source our data through distribution agreements with a number of wholesale market data providers. In the case of US equities, the data is sourced directly from a secure connection to CTA and UTP Feed, and historical financials are collated from SEC filings."

=== links ===
SEC Observes Scaling Issues in XBRL Tagging, July 21, 2025
"For example, one filer reported a public float of $78 million in its HTML filing, but reported a public float of $78 in its XBRL data."
xbrl.us - SEC scaling issues

Why Tagging Errors mean Trouble, September 25, 2020
"With a huge number of report-users looking straight to the XBRL data, mis-tagging XBRL can corrode a company’s reputation. Despite that, the XBRL US Data Quality Committee (DQC) has found that 34% of the most recent SEC filings include at least one error. To be fair, many of these are minor errors amongst thousands of disclosed concepts. However, these are the kinds of errors that can be easily caught by companies prior to filing because the DQC rule set exists."
xbrl.org - Why tagging errors mean trouble

Author: unquarked
Subject: Historical stock data
Date: 11/15/24
AlphaDog replied "I have not had a good experience with Wisesheets."
lizgdal replied "Wisesheets looks interesting. Sounds similar to some other start-ups that are getting the data directly from the annual reports, but coverage might be spotty (some tickers not covered). All the data vendors seem to have some mistakes in their data, and so it's a question of how many mistakes."
unquarked writes on Historical stock data

Author: Aussi
Subject: Retrieving Historical price Data
Date: 03/09/25
"I am trying Wisesheets that was also mentioned. For Excel, Wisesheets does not work on Excel 2019 for retrieving pricing, it does work for getting other data. They advised that you need Microsoft 365. On Goooglesheets it works fine. The only issue I have noticed is that although there is a formula for adjusted prices, the most recent dividend is not included (at least in the three stocks I checked, XOM, APPL and GOOG). I have written to them and received a reply that they would check with their vendor."
Aussi writes on Retrieving Historical price Data

"I purchased a Wisesheets subscription on June 2nd, 2025, and discovered that the platform does not support the securities I need (European mutual funds and ETFs). I had attempted to research the instrument coverage beforehand, but the website lacks a searchable directory and the free trial did not clearly show these limitations. Within hours of purchase, I sent a polite refund request explaining the situation and even acknowledged that Wisesheets appears to be a well-designed platform with smooth interface and quick data loading. However, I have received no response from the company and no refund."
https://www.trustpilot.com/review/www.wisesheets.i...