Is Practical Web Tools really free?

Yes, all 300+ tools are completely free with no hidden costs. There are no premium tiers, no usage limits, and no subscriptions. The AI chat feature is also 100% free because it runs on your own computer using Ollama.

Are my files uploaded to your servers?

No. All file processing happens directly in your browser using WebAssembly technology. Your files never leave your device. This makes Practical Web Tools ideal for sensitive documents like contracts, medical records, and financial statements.

What file formats can I convert?

Practical Web Tools supports PDF conversion (to Word, Excel, PowerPoint, images, text), image formats (JPG, PNG, WebP, HEIC, GIF, BMP), audio formats (MP3, WAV, FLAC, OGG, M4A, AAC, OPUS), and document compression (ZIP, 7Z, GZIP, RAR).

How does the free AI chat work?

The AI chat uses Ollama, a free open-source tool that runs AI models locally on your computer. After a one-time setup (about 5 minutes), you can chat with models like Llama 3.2 and Mistral completely offline. Your conversations are never sent to any external servers.

Do I need to create an account?

No account or signup is required. All tools work immediately with no registration. For AI chat, you just need to install Ollama once on your computer.

Is there a file size limit?

Most tools handle files up to 100MB. Since processing happens locally in your browser, the actual limit depends on your device's memory. For very large files, we recommend using our Split PDF or Compress Files tools first.

Does it work on mobile devices?

Yes. All file conversion tools work on smartphones and tablets. The AI chat feature requires a desktop computer (Windows, Mac, or Linux) because Ollama needs to run locally.

100% Free - No Signup Required

Free Confidence Interval Calculator

Name: Free AI Chat - Offline AI Assistant with Ollama
Rating: 4.9 (256 reviews)
Author: Practical Web Tools

Calculate confidence intervals for means and proportions at any confidence level.

Files Never Leave Your DeviceInstant ProcessingNo Watermarks

Calculate CI

Quick Answer

A 95% confidence interval means 95% probability the true value falls within the range. CI = mean ± (z × standard error).

Key Facts about Confidence Interval Calculator:

95% CI most common
Higher confidence = wider interval
Larger sample = narrower CI
95% uses z=1.96
Margin of error = half CI width

Why Use Our Confidence Interval Calculator?

CI tools:

📊

Multiple Levels

90%, 95%, 99% CI.

📈

Means & Proportions

Both calculation types.

🔢

Sample Size

Account for n.

📉

Margin of Error

Calculate MOE.

⚡

Instant

Quick results.

🔒

Private

Data stays secure.

Try Confidence Interval Calculator Now

How to Confidence Interval Calculator in 3 Easy Steps

Calculate CI:

Enter Data

Sample statistics.

Choose Level

Confidence level.

Get Interval

See CI range.

Start Now - It's Free

Why Use Our Calculator?

Multiple confidence levels

Means and proportions

Shows formula

Instant results

Calculate CI

📊

Statistics

Confidence intervals made easy

Common Use Cases for Confidence Interval Calculator

Perfect for:

Research

Statistical analysis.

Calculate

Surveys

Margin of error.

Compute

Quality Control

Process limits.

Analyze

Frequently Asked Questions

Everything you need to know about our confidence interval calculator

What is 95% confidence interval?

It means 95% probability the true population value falls within the calculated range.

Still have questions? Try the tool yourself!

Calculate CI

Related Tools You Might Like

Explore more free tools to boost your productivity

Standard Deviation Calculator

Calculate SD

Sample Size Calculator

Determine n

Calculate CI Now

Free confidence interval calculator.

Calculate CI

No signup required. Start using immediately.