Free statistical analysis tools for quality
The statistics behind quality and Six Sigma, without the statistics software: paste your data, get the answer and a plain-language interpretation, and export a clean report.
- 100% free
- No sign-up
- Paste from Excel
- Export to PDF, PNG & Excel
Run Chart
Plot data over time with the median and detect shifts, trends and unusual numbers of runs.
Open tool → Free toolProcess Capability Analysis (Cp/Cpk, Pp/Ppk)
Calculate Cp, Cpk, Pp, Ppk and expected PPM with a capability histogram and a normality test.
Open tool → Free toolMeasurement System Analysis
Check gauge bias and repeatability (Cg, Cgk) and linearity across the measuring range.
Open tool → Free toolGage R&R
Run a crossed Gage R&R study by ANOVA: %Study Var, %Tolerance and number of distinct categories.
Open tool → Free toolHypothesis Testing
Run t-tests and proportion tests with p-values, confidence intervals and a plain-language conclusion.
Open tool → Free toolRegression Analysis
Fit simple or multiple linear regression with p-values, residual plots and predictions.
Open tool → Free toolANOVA
Compare several group means with one-way ANOVA, Welch's test and Tukey comparisons.
Open tool → Free toolDesign of Experiments
Plan 2-level factorial experiments, then find the significant effects and the best settings.
Open tool → Free toolSampling Plans
Find AQL sampling plans (Z1.4 / ISO 2859-1) with OC curve, LTPD and AOQL.
Open tool →Which statistical tool should you use?
| Tool | Use it when… | What you get |
|---|---|---|
| Measurement System Analysis | You need to know if a gauge is accurate (bias, linearity) | Cg, Cgk, bias test, linearity |
| Gage R&R | You need to know if a gauge and its operators are precise enough | %Study Var, %Tolerance, ndc |
| Run Chart | You want to see if a measure changes over time, or after a change | Median, shifts, trends, runs test |
| Process Capability Analysis | You need to know if a process meets its specification | Cp, Cpk, Pp, Ppk, PPM |
| Hypothesis Testing | You want to compare one or two groups, or a rate with a target | p-value, confidence interval, effect size |
| ANOVA | You want to compare three or more groups | F test, Tukey comparisons |
| Regression Analysis | You want to model a result from process settings | Equation, R², significant predictors |
| Design of Experiments | You want to find the best settings of several factors | Effects, interactions, best settings |
| Sampling Plans | You need to decide how many units to inspect per lot | n, Ac/Re, OC curve, AOQL |
A typical sequence in an improvement project
- Trust the data. Check the gauge with MSA and Gage R&R.
- Understand the baseline. Plot the data over time with a run chart or control chart, then measure capability.
- Test the causes. Compare groups with hypothesis tests and ANOVA, and model relationships with regression.
- Optimize. Find the best settings with a designed experiment.
- Control. Monitor the new process, and set sampling plans for incoming and final inspection.
From one-off studies to controlled evidence
A study is only useful if its conclusions are acted on and its data can be trusted. Cloudtheapp manages equipment and calibration schedules, and links your evidence to validation, change control and CAPA in one validated system.
Frequently asked questions
Do I need statistical software to use these tools?
No. Each tool does the calculations in your browser: paste your data from Excel and get the results, charts and a plain-language interpretation. The methods follow the usual references (AIAG MSA and SPC manuals, Montgomery, ANSI/ASQ Z1.4) so results match common statistical packages.
Which tool should I start with?
Start by checking the measurement system (MSA and Gage R&R), then look at the data over time (run chart or control chart), then the capability against the specification. Use hypothesis tests, ANOVA and regression to test causes, and design of experiments to optimize.
Is my data private?
Yes. The data stays in your browser and is saved only on your device. Nothing is uploaded unless you export a file yourself.
Are these tools suitable for Six Sigma projects?
Yes. They cover the core statistics of the Measure, Analyze and Improve phases of DMAIC: MSA, capability, hypothesis testing, ANOVA, regression and factorial DOE, with exports for your project report.
Are the tools really free?
Yes. Every tool is free, needs no account, and exports to PDF, PNG, Excel and CSV.
Make statistical evidence part of your quality system
Cloudtheapp keeps the evidence behind your studies under control: calibrated equipment, validation records, change control and CAPA, linked in one validated cloud QMS.