Best Excel Add-in 2026 · Global Excel Summit

Why PerfectXL: 11 reasons to trust Excel again

Excel can feel opaque, uncontrollable and error-prone. It doesn’t have to be. PerfectXL turns every spreadsheet into a clear picture: where the risks are, how the model is built, and what changed since the last version.

You prevent blunders, save time, take on even the hardest model, and get your spreadsheets ready for your newest colleague: AI.

  • Works inside your existing Excel
  • Analyses locally, nothing uploaded
  • 14-day free trial

It’s without a doubt Top 5 in the world in terms of mitigating human errors, visualizing changes and analyzing potential risk factors.

Pascal Schoneberg

M1KLLC

11 reasons, backed by research

What changes when your
team uses PerfectXL

Each reason links to independent research. Pick your role to see the reasons
that matter most to you.

Reason 01

Prevent costly blunders

One wrong cell reference can cost millions. PerfectXL scans entire models for dozens of concrete risks and finds errors before they do damage.

Up to 94%

of business spreadsheets contained errors in the most thorough field audits

Poon et al., 2024

For financial controllers, modellers, actuaries, treasury and the CFO who signs off

Sources (5)

  1. Acuity Training survey (2022) 98% have seen an Excel error cost their employer money
  2. EuSpRIG Horror Stories Documented spreadsheet incidents since 1995
  3. Financial Times via Slashdot (2024) Norway’s wealth fund loses ~$92M to an Excel error
  4. Poon, Lau, Yu & Tang (2024) Spreadsheet quality assurance: a literature review
  5. RTV Utrecht (2024) €40M budget gap from one missed inflation correction

Reason 02

Save time on spreadsheet work

Building, checking, cleaning up, finding out why numbers don’t add up. PerfectXL shows what’s going on at a glance and guides you through fixing or extending models.

5.4 hrs

a day the average finance professional spends in spreadsheets
Datarails, 2025

For controllers, FP&A analysts, accountants in busy season, consultants and model builders

Sources (4)

  1. Acuity Training (2022) 38% of working time spent in Excel
  2. Datarails, Excel Generations (2025) 5.4 hours per day in spreadsheets
  3. FP&A Trends 2024 & AFP/APQC Only a quarter to a third of time goes to analysis
  4. Unit4 via CFOtech (2025) 61% say reporting pressure harms wellbeing

Reason 03

Get crystal-clear Excel models

A model nobody understands convinces nobody. PerfectXL makes it clear to every reader: you, your successor, the documentation and AI.

4 readers

every good model has: its user, the successor, the documentation and AI
Szameitat, Exemplum, 2026

For model builders defending their work, reviewers, auditors and regulators

Sources (4)

  1. DNB & AFM, Explainable AI Explainability as a core principle
  2. Hermans et al., TU Delft (ICSE 2011) Dataflow diagrams speed up understanding
  3. Microsoft Research, SpreadsheetLLM (2024) Raw spreadsheets are a problem for LLMs
  4. Szameitat, “I Thought I Knew PerfectXL” (2026)The four-reader perspective

Reason 04

Use AI efficiently in Excel

Copilot, Claude and ChatGPT can do a lot, but not calculate cheaply or exactly. PerfectXL does the exact analysis without using a single token and gives AI compact, structured input.

59%

AI adoption in finance stalled in 2025, held back by data quality and skills
Gartner, 2025

For CFOs, finance managers, IT and data leads, and analysts working with Copilot or ChatGPT

Sources (4)

  1. Gartner, AI in Finance Survey (2025)  AI-Adoption steady at 59%
  2. Microsoft & LinkedIn, Work Trend Index (2024) 75% of knowledge workers use AI
  3. Microsoft Research, SpreadsheetLLM (2024)Compressing and structuring improves LLM results
  4. Volkskrant (2026, paywall) Rising AI costs at Uber, Citigroup, KPMG

Reason 05

Change models with confidence

Afraid to touch a formula because you don’t know what breaks? See what depends on it beforehand, and exactly what changed afterwards.

“Don’t touch it”

the policy researchers find around vital legacy spreadsheets nobody understands anymore
Hodnigg & Mittermeir, 2008

For anyone inheriting, repairing or merging a model, especially one built by someone else or an AI agent

Sources (5)

  1. Feathers, Working Effectively with Legacy Code
  2. Hermans et al., Spreadsheets are Code
  3. Hodnigg & Mittermeir, EuSpRIG (2008) The “don’t touch it” policy
  4. Lehman, Laws of Software Evolution (1980)
  5. Murphy, Spreadsheet Hell (2007)

Reason 06

Prove spreadsheet compliance

Auditors, management and IT don’t take Excel work on trust. PerfectXL tests models against accepted standards and gives you the evidence in black and white.

2024

since May, UK banks’ spreadsheets explicitly fall under PRA model-risk rules (SS1/23)
Bank of England PRA

For banks, insurers, pension funds, listed companies, and their risk, compliance and audit teams

Sources (5)

  1. ICAEW, Twenty Principles for Good Spreadsheet Practice
  2. PRA Supervisory Statement SS1/23
  3. PwC, Spreadsheets & SOX 404 (2004)
  4. NBA, Standard 315 explained
  5. Panko, Spreadsheets and Sarbanes-Oxley (2006)

Reason 07

Keep spreadsheets healthy for years

Spreadsheets outlive reorganisations, migrations and the colleague who knew how it worked. PerfectXL keeps them understandable, transferable and modern.

5 yrs · 13 users

the average spreadsheet’s lifespan and the number of people who use it
Hermans et al., TU Delft

For controllers who inherited a model, IT managers planning migrations, actuaries and team leads

Sources (3)

    1. Galan (2023), organizational amnesia
    2. Hermans et al., Analyzing and Visualizing Spreadsheets (2013)
    3. Thyssenkrupp v HMRC [2024] UKUT 79 £8.9M assessment, seven years of litigation

Reason 08

See how a model works

A spreadsheet is a wall of cells. Most people grasp a picture faster. PerfectXL puts everything in view, from model structure to a single formula.

58%

of a developer’s time goes to understanding what already exists, not building
Xia et al., IEEE TSE, 2018

For reviewers and auditors in unfamiliar models, consultants explaining to clients, trainers and team leads

Sources (3)

  1. Hermans, Pinzger & Van Deursen (ICSE 2011)
  2. Nelson, Reed & Walling (1976) Pictorial superiority effect
  3. Xia et al., Measuring Program Comprehension (2018)

Reason 09

Trust other people’s models, including AI’s

Nobody has time to check a colleague’s or an AI’s work cell by cell. PerfectXL gives you grounded trust, and shows to what extent a model was built by AI.

78%

of AI users bring their own AI tools to work, often without telling anyone
Microsoft & LinkedIn, 2024

For due diligence and M&A teams, investors, credit and risk managers, auditors and reviewers

Sources (3)

  1. Butler, AIB/Allfirst fraud (EuSpRIG) $691M hidden by manipulating a spreadsheet
  2. Microsoft & LinkedIn, Work Trend Index (2024)
  3. Poon et al. (2024)

Reason 10

Work consistently, as a team

Excel works best when everyone builds the same way. PerfectXL’s Rulebook enforces that consistency: for you, your team and AI.

FAST

the modelling standard that puts consistency at its core, recognised by ICAEW
fast-standard.org

For team leads and finance managers with multiple builders, and modellers working to a house standard

Sources (3)

  1. FAST Standard
  2. Hermans et al., Detecting Code Smells in Spreadsheet Formulas (2012)
  3. Panko, Recommended Practices for Spreadsheet Testing (2006)

Reason 11

Impress your clients

Deliver solid insights and reports within minutes. Your client won’t even see how little time it took.

2026

PerfectXL named Best Excel Add-in at the Global Excel Summit
Global Excel Awards

For consultants, corporate finance advisors, interim controllers and anyone pitching to a new client

Sources (3)

    1. Asch, Forming Impressions of Personality (1946)The primacy effect
    2. Global Excel Awards 2026
    3. Szameitat, “I Thought I Knew PerfectXL” (2026)

One application

Eleven reasons,
four capabilities,
one suite

Every reason on this page comes from the same PerfectXL application inside Excel. No separate tools to buy, learn or get past IT.

Formula inspection & AI prompts

Long formulas untangled, smart prompts for AI

Visualization

Model structure & data flows

Version compare

Exactly what changed between versions

Risk detection

Dozens of inspections, ranked findings

Questions

Frequently asked
questions about PerfectXL

Something else? Ask us directly. A real specialist answers.

What is PerfectXL?

PerfectXL is an Excel add-in that analyses spreadsheets for risks, visualises how a model is built, explains long formulas and compares versions.

It helps finance, audit and modelling teams prevent errors, save review time and prove their models are under control.

How do I find errors in a large Excel spreadsheet?

Manual review only covers what a reviewer thinks to look at. PerfectXL scans the complete workbook for dozens of concrete risks, such as circular references, hardcoded numbers in formulas, error-prone functions and incorrect references, and returns a report with suggested fixes.

Can I use PerfectXL alongside Copilot, ChatGPT or Claude?

Yes. PerfectXL does the exact analysis without using any AI tokens, then generates lists, reports and smart prompts that AI tools can work with directly. It can also share model structure without confidential data and check AI-generated formulas.

Does my workbook leave my computer?

No. PerfectXL analyses the workbook locally on the machine it runs on. Nothing is uploaded and nothing is retained.

Does PerfectXL help with SOX, PRA SS1/23 or ISA 315 requirements?

PerfectXL tests models against accepted standards for good spreadsheet practice, optionally via a Rulebook tailored to your organisation, and produces audit reports and documentation that show spreadsheets are under control.

Who uses PerfectXL?

Financial controllers, FP&A analysts, financial modellers, actuaries, internal and external auditors, risk and compliance officers, and consultants who review or build business-critical Excel models.

See all eleven on your own workbook

Start a free trial and scan the model that worries you most, or book a demo and we’ll walk through it with you.

  • Run it on your own file, not a canned dataset
  • Nothing leaves your environment
  • 14 days, all capabilities, no card

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