---
title: "Reporting Guardrails"
slug: "reporting-guardrails"
updated: 2026-10-08T17:15:55Z
published: 2026-10-08T17:15:55Z
canonical: "help.nucleussec.com/reporting-guardrails"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.nucleussec.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Reporting Guardrails

### What are report size guardrails?

Report size guardrails help make sure the reports you request come back to you quickly and reliably. When a report covers a very large dataset, generation can run for a long time, sometimes hours, before you know whether a usable file will be produced. While a very large report is being built, other reports you've queued can also be held up waiting behind it.

To keep your reporting experience predictable, Nucleus checks the expected size of a report before it starts. If the report would be larger than the recommended size for its format, Nucleus surfaces that up front so you can adjust the scope and get results in a timeframe you can plan around.

### When guardrails apply

Guardrails are on by default for your organization and check the size of a report at two points:

1. **When you create or schedule a report**. As you choose a project, filters, and report type, Nucleus estimates the number of rows the report would include. If the estimate is above the recommended size, the **Generate** or **Save** button is temporarily disabled and this message appears: “*The report you are trying to create is too large. Please apply additional filters to reduce the size and try again.*”
2. The estimate updates in real time as you adjust filters, so the button re-enables as soon as the report fits.

When a scheduled report runs. Nucleus re-checks the estimate at run time in case the underlying data has grown since the schedule was configured. If the estimate is above the recommended size, the run does not proceed and the entry on the Scheduled Reports grid is marked with: “*Warning - report exceeded maximum results*”

No file is produced for that run and your schedule is preserved. Open the schedule, narrow the scope, and the next run will use the updated filters.

### Report size by format

Each output format has a size that works well for how the format is typically used. Word and PDF are formatted documents designed for readable summaries, so their maximum size is smaller. Excel and CSV are tabular formats designed for working with data at volume, and their maximum size is much larger.

#### Row limits by report

Every report has a maximum number of rows it can be generated for. Most reports will use the default for their output format.

**Default limits by format**

| Format | Maximum rows per report |
| --- | --- |
| Word ( .docx ) | 10,000 |
| PDF ( .pdf ) | 5,000 |
| Excel ( .xlsx ) | 1,000,000 |
| CSV ( .csv ) | 1,000,000 |

A "row" is one finding, asset, or line item the report includes, matching the count you would see in the underlying view before the report is generated.

**Reports with their own limit**

These reports do not use the default for their format. If your report is listed here, this limit applies instead.

| Report | Format | Row limit |
| --- | --- | --- |
| **Custom Report pdf** | PDF | 100,000 |
| **Vulnerability Summary pdf** | PDF | 100,000 |
| **Explore/ NQL Export** | Excel | 20,000 |

### Where guardrails apply today

A guardrail works by estimating a report's size before it runs, and that estimate is built for each report individually. Reports that have one are checked against the limits above. Reports that do not yet have one generate without a size check.

Coverage is being rolled out in order of impact, starting with the reports most likely to run at sizes that cause slow or failed generation, and the reports used most widely across Nucleus. If a report is covered, you will see the size warning described above as you configure it; if no warning appears, that report is not yet checked or your criteria is a good fit for the report.

Coverage expands over time, and the goal is for every Nucleus report and export to be protected. When a report you use gains a size check, the behavior described in this article takes effect automatically. Your existing scheduled reports on that type continue to run, and each new run validates against the limit that applies at that moment.

### If you receive a size warning

You have several options to bring a report within the recommended size while still getting the information you need.

**1. Narrow the or split the scope.**

The report size reflects the data currently in view. Adding filters that match your reporting goal reduces the size directly. Common ways to narrow the scope include:

- Severity (for example, Critical and High only)
- Asset group

When you need the full dataset, you can split it into several smaller reports along a natural boundary such as asset group, business unit, severity band, or project. Each smaller report is validated on its own and runs independently.

**3. Choose the format that fits your use case.**

Word and PDF are great for executive summaries and narrower slices where readability matters most. Excel and CSV are designed for working with data at volume, so they accommodate much larger row counts.

**4. Save the working scope as a scheduled report.**

Once you have a scope that fits, saving it as a scheduled report gives you a fresh copy on each run without having to reconfigure filters.