House Cleaning in Pittsburgh: Prices, Services & How to Choose the Best Cleaner (2026 Guide)

Tips from Cordially Clean / / March 9, 2026

House Cleaning in Pittsburgh: Prices, Services & How to Choose the Best Cleaner (2026 Guide)

Keeping your home clean can be difficult when you’re balancing work, family, and everything else life throws your way. That’s why many homeowners are turning to professional house cleaning services in Pittsburgh to keep their homes spotless without sacrificing their free time.

Whether you live in a downtown apartment, a suburban home in the North Hills, or a townhouse in the South Side, hiring a professional cleaner can make a huge difference in your day-to-day life. In this guide, we’ll cover everything Pittsburgh homeowners need to know about hiring a cleaning service, including average costs, what’s included, and how to choose the right company.

Average Cost of House Cleaning in Pittsburgh

One of the first questions homeowners ask is how much professional cleaning costs. The price of house cleaning in Pittsburgh can vary depending on the size of your home, the type of service you need, and how often you schedule cleanings.

Typical cleaning prices in the Pittsburgh area include:

Home SizeAverage Cost
1 bedroom apartment$80 – $150
2–3 bedroom home$120 – $250
4+ bedroom home$200 – $400

Deep cleaning services usually cost more because they require additional time and detail. Many cleaning companies also offer discounted rates for recurring services such as weekly or bi-weekly cleaning.

Factors that affect cleaning prices include:

  • Square footage of the home

  • Number of bathrooms

  • Level of dirt or clutter

  • Pets in the home

  • Special services like oven or fridge cleaning

For most households, a standard cleaning takes between 2 and 4 hours, depending on the size of the home.

Types of House Cleaning Services Available in Pittsburgh

Professional cleaning companies offer several types of services depending on your needs.

Regular House Cleaning

Regular cleaning is the most common service. It’s typically scheduled weekly, bi-weekly, or monthly.

A regular cleaning usually includes:

  • Dusting surfaces

  • Vacuuming carpets and rugs

  • Sweeping and mopping floors

  • Cleaning bathrooms

  • Wiping kitchen counters and appliances

  • Emptying trash bins

This type of service keeps your home consistently clean without needing constant upkeep from you.

Deep Cleaning Services

Deep cleaning goes beyond basic maintenance and targets areas that don’t get cleaned regularly.

Deep cleaning often includes:

  • Scrubbing grout

  • Cleaning baseboards

  • Washing cabinet fronts

  • Removing soap scum

  • Cleaning behind appliances

  • Detailed dusting of vents and blinds

Many homeowners schedule deep cleaning once or twice per year.

Move-Out or Move-In Cleaning

If you’re moving, a professional cleaner can prepare the home for the next occupant.

Move-out cleaning usually includes:

  • Inside cabinets and drawers

  • Appliance cleaning

  • Full bathroom sanitation

  • Floor washing and vacuuming

  • Baseboard cleaning

This type of service is popular with renters who want to ensure they receive their full security deposit.

Apartment Cleaning

Apartment cleaning services are designed for smaller spaces and typically take less time than full-size homes. Many Pittsburgh residents living downtown or in neighborhoods like Shadyside or Oakland choose recurring apartment cleaning services.

Short-Term Rental Cleaning

If you own an Airbnb or short-term rental property, fast and reliable cleaning is essential between guest stays. Professional cleaners can handle laundry, restocking essentials, and preparing the property for new guests.

What’s Included in a Professional House Cleaning

While every cleaning company has its own checklist, most services follow a similar structure.

Kitchen Cleaning

The kitchen is one of the most heavily used areas of the home and requires detailed attention.

Typical kitchen cleaning tasks include:

  • Wiping countertops

  • Cleaning sinks and faucets

  • Cleaning exterior appliances

  • Vacuuming and mopping floors

  • Removing trash and recycling

Bathroom Cleaning

Bathrooms are sanitized and disinfected during professional cleaning.

Bathroom cleaning typically includes:

  • Scrubbing toilets

  • Cleaning showers and bathtubs

  • Wiping mirrors and fixtures

  • Sanitizing sinks

  • Mopping floors

Living Areas

Common areas are dusted and cleaned to maintain a fresh and welcoming environment.

Tasks often include:

  • Dusting furniture

  • Cleaning surfaces

  • Vacuuming carpets

  • Sweeping or mopping floors

Bedrooms

Bedrooms receive light cleaning and dusting to keep them comfortable and tidy.

Typical bedroom tasks include:

  • Dusting surfaces

  • Vacuuming floors

  • Straightening bedding

  • Cleaning mirrors

How Often Should You Schedule House Cleaning?

How often you should hire a cleaner depends on your lifestyle, family size, and how much time you want to spend cleaning.

Weekly Cleaning

Best for:

  • Busy professionals

  • Families with children

  • Homes with pets

Weekly cleaning keeps homes consistently spotless.

Bi-Weekly Cleaning

Bi-weekly service is the most common choice for homeowners.

It balances cost and convenience while keeping the home well maintained.

Monthly Cleaning

Monthly cleaning works well for smaller households or individuals who perform basic cleaning themselves but want occasional professional help.

One-Time Deep Cleaning

A one-time deep clean is ideal when:

  • Preparing for guests

  • Moving into a new home

  • After renovation projects

  • Seasonal spring cleaning

How Long Does House Cleaning Take?

Cleaning time depends mainly on the size and condition of the home.

Typical cleaning times:

Home TypeEstimated Time
Studio / 1 bedroom1–2 hours
2–3 bedroom home2–4 hours
4+ bedroom home4–6 hours

Homes that haven’t been professionally cleaned in a while may take longer during the first visit.

Areas Served Around Pittsburgh

Professional cleaning services typically serve neighborhoods throughout the greater Pittsburgh area.

Common service areas include:

  • Wexford

  • Cranberry Township

  • Franklin Park

  • Sewickley

  • Ross Township

  • McCandless

  • Allison Park

  • Shadyside

  • Oakland

  • South Side

If you live in the North Hills or surrounding suburbs, many cleaning companies offer flexible scheduling and recurring service plans.

How to Choose the Best House Cleaning Service in Pittsburgh

Not all cleaning services are the same. When choosing a company, look for these important qualities.

Licensed and Insured

A reputable cleaning service should be fully insured to protect both workers and your home.

Background-Checked Staff

Many professional companies perform background checks on employees to ensure customer safety and trust.

Transparent Pricing

Look for companies that clearly explain their pricing structure and provide upfront estimates.

Positive Reviews

Check online reviews to see what other homeowners in Pittsburgh are saying about their experience.

Eco-Friendly Cleaning Options

Some homeowners prefer non-toxic or eco-friendly cleaning products, especially for homes with children or pets.

Professional Cleaning Tips to Keep Your Home Tidy

Even with professional help, a few habits can keep your home cleaner between visits.

Helpful cleaning tips include:

  • Clean from top to bottom to avoid spreading dust

  • Use microfiber cloths to trap dust effectively

  • Vacuum high-traffic areas more frequently

  • Keep cleaning supplies easily accessible

These small habits can make a big difference in maintaining a clean home.

When Hiring a Professional Cleaner Makes the Most Sense

Hiring a cleaner isn’t just about convenience—it can also save time and reduce stress.

Many Pittsburgh homeowners hire cleaning services when:

  • They work long hours

  • They’re preparing to sell their home

  • They’re moving in or out of a property

  • They want more free time on weekends

For busy households, professional cleaning services can significantly improve quality of life.

Frequently Asked Questions About House Cleaning in Pittsburgh

How much does house cleaning cost in Pittsburgh?

Most homes cost between $120 and $250 per visit, depending on size and service type.

How long does a professional cleaning take?

A typical cleaning takes 2–4 hours, though larger homes may take longer.

What is included in a deep cleaning service?

Deep cleaning usually includes baseboards, grout scrubbing, appliance cleaning, and detailed dusting.

Is it cheaper to schedule recurring cleaning?

Yes. Many companies offer discounted pricing for weekly or bi-weekly services.

Final Thoughts

Hiring a professional cleaner can make maintaining your home much easier. Whether you need regular maintenance, a deep cleaning, or move-out services, there are many reliable options for house cleaning in Pittsburgh.

By understanding typical pricing, available services, and what to look for in a cleaning company, you can confidently choose a service that fits your needs and keeps your home looking its best.

The Ultimate Deep Cleaning Guide for Homes in Allegheny County

Tips from Cordially Clean / / March 2, 2026

The Ultimate Deep Cleaning Guide for Homes in Allegheny County

Keeping your home clean and healthy is more important than ever — especially in today’s busy world. At Cordially Clean, we specialize in professional deep cleaning services designed to restore sparkle and comfort to homes across Allegheny County, including Sewickley, Wexford, Fox Chapel, Upper St. Clair, Mt. Lebanon, and North Hills neighborhoods.

Whether you’re preparing for a special occasion, moving into a new home, or just tackling months of buildup, our team delivers meticulous, detail-oriented cleaning that homeowners trust.

Why Deep Cleaning Matters

Many homeowners focus on surface cleaning — wiping counters and vacuuming floors — but this isn’t enough. Deep cleaning goes beyond the obvious:

  • Sanitizing bathrooms and kitchens

  • Cleaning behind appliances and furniture

  • Dusting baseboards, vents, and ceiling fans

  • Removing built-up grime from high-traffic areas

A professional deep clean not only makes your home look immaculate but also improves indoor air quality, reduces allergens, and protects your family’s health.

Our Service Areas: Neighborhoods We Serve

At Cordially Clean, we’re proud to serve high-demand neighborhoods across Allegheny County, offering deep cleaning services customized to your home’s unique needs.

1️⃣ Sewickley

Luxury homes and busy families in Sewickley rely on our white-glove deep cleaning services for spotless kitchens, bathrooms, and living spaces.

2️⃣ Wexford

For Wexford residents, we provide recurring and one-time deep cleans, helping homes stay guest-ready year-round.

3️⃣ Fox Chapel

Our professional team specializes in estate-level cleaning, focusing on every detail from baseboards to ceiling fans.

4️⃣ Upper St. Clair

Busy households in Upper St. Clair love our recurring cleaning plans that keep homes consistently pristine without the stress.

5️⃣ Mt. Lebanon

From move-in/move-out cleans to seasonal deep cleaning, we help Mt. Lebanon homeowners maintain beautiful, healthy homes.

6️⃣ North Hills & Surrounding Communities

We serve all surrounding neighborhoods, including Shadyside, Squirrel Hill, Bethel Park, and Robinson Township, providing dependable, thorough cleaning services for families, professionals, and homeowners preparing their homes for sale.

When to Schedule a Deep Clean

A professional deep clean is perfect for:

  • Seasonal cleaning (spring refresh, holiday prep)

  • Post-event or party cleanup

  • Move-in or move-out cleaning

  • Allergy season preparation

  • Busy households needing recurring attention

Not sure if your home needs a deep clean? If dust, grime, or clutter is piling up in areas you rarely clean, it’s time to call in the experts.

Why Homeowners Choose Cordially Clean

  • Experienced Professionals: Our team is trained, insured, and detail-oriented.

  • Custom Cleaning Plans: We tailor each cleaning to your home’s size, layout, and unique needs.

  • Eco-Friendly Products: Safe for children, pets, and your home’s surfaces.

  • Local Expertise: Serving Allegheny County neighborhoods for years, we understand the homes and expectations in each community.

Book Your Deep Cleaning Today

Don’t wait to experience the benefits of a professional deep clean. Whether you’re in Sewickley, Wexford, Fox Chapel, or any Allegheny County neighborhood, Cordially Clean makes your home sparkle, protects your family’s health, and frees your time for the things that matter most.

Call us today or schedule online to get a personalized quote and book your next deep cleaning.

Why Busy Homeowners in Pittsburgh’s Upscale Neighborhoods Choose Professional House Cleaning

Expansion, Tips from Cordially Clean / / February 12, 2026

Why Busy Homeowners in Pittsburgh’s Upscale Neighborhoods Choose Professional House Cleaning

In established Pittsburgh neighborhoods like Squirrel Hill, Shadyside, Fox Chapel, Sewickley, Upper St. Clair, Mt. Lebanon, and Highland Park, time is often the most valuable asset. Between careers, family schedules, travel, and social commitments, maintaining a spotless home can become overwhelming — even though a clean home is essential for comfort, health, and peace of mind.

That’s why more homeowners in Pittsburgh’s sought-after communities are turning to professional house cleaning services like Cordially Clean.

A Clean Home Isn’t Just About Appearance

For many homeowners in areas like Shadyside and Squirrel Hill, cleaning used to be about presentation. Today, it’s about:

  • Healthier indoor air quality

  • Reduced allergens and dust

  • Lower daily stress

  • A calm, organized environment

  • Protecting premium surfaces and finishes

Homes in neighborhoods such as Fox Chapel, Sewickley, and Mt. Lebanon often feature hardwood floors, stone countertops, tile bathrooms, detailed trim, and custom fixtures. These surfaces require proper care — not rushed or harsh cleaning methods.

Professional house cleaning helps preserve both beauty and long-term home value.

Time Is the Real Luxury

Professionals and families in Upper St. Clair, Highland Park, and Shadyside understand that outsourcing time-consuming tasks creates more freedom.

Instead of spending weekends scrubbing or dusting, our clients use their time to:

  • Be with family

  • Entertain

  • Travel

  • Focus on work

  • Relax

Recurring house cleaning turns home maintenance into something that simply gets handled.

Consistency Matters in Larger Homes

Many homes in Sewickley and Fox Chapel are spacious, making it easy for dust and buildup to go unnoticed. Consistent professional cleaning prevents that.

Our recurring service keeps homes in top condition with:

  • Regular dusting of surfaces and fixtures

  • Careful kitchen and bathroom cleaning

  • Proper floor care

  • Detail work that stops buildup before it starts

When cleaning happens on a schedule, the home always feels maintained.

Discretion and Trust

Homeowners in established communities value privacy, reliability, and professionalism. Inviting someone into your home requires trust.

Our team provides respectful, professional service that homeowners across Pittsburgh’s premier neighborhoods rely on.

Deep Cleaning Protects High-End Homes

Properties in Squirrel Hill, Mt. Lebanon, and Shadyside often have detailed features — baseboards, vents, grout lines, and specialty surfaces that collect hidden dirt.

Deep cleaning services help:

  • Maintain bathrooms and kitchens

  • Protect flooring and trim

  • Restore freshness

  • Prevent long-term surface wear

Eco-Friendly Cleaning for Modern Families

Many families in Highland Park, Upper St. Clair, and Fox Chapel prefer safer cleaning solutions. Professional services can provide effective cleaning while being mindful of indoor air quality, children, and pets.

A Smart Choice for Pittsburgh Homeowners

Professional house cleaning is no longer an occasional luxury — it’s a practical solution for homeowners who value their time and want their homes maintained at a higher standard.

Cordially Clean provides reliable, detail-focused house cleaning for homes throughout:

Squirrel Hill • Shadyside • Fox Chapel • Sewickley • Upper St. Clair • Mt. Lebanon • Highland Park

If you’re ready to spend less time cleaning and more time enjoying your home, professional cleaning is a smart investment.

The Ultimate Deep House Cleaning Checklist Most Homeowners Miss

Tips from Cordially Clean / / February 2, 2026
Bright and modern bathroom featuring neatly stacked towels, a potted plant, and cleaning supplies on a countertop.

The Ultimate Deep House Cleaning Checklist Most Homeowners Miss

When people think their home is “clean,” they usually mean surfaces look tidy. But true deep house cleaning goes far beyond wiping counters and vacuuming floors.

Professional cleaners know that the biggest buildup of dirt, bacteria, and allergens happens in the small, overlooked areas. This checklist shows what a meticulous, detail-oriented cleaning really includes — and why it makes such a difference.

What Is Deep House Cleaning?

Deep cleaning focuses on buildup, hidden grime, and neglected areas, not just visible surfaces. It’s typically recommended:

  • Before hosting guests

  • During seasonal resets (spring/fall)

  • After renovations

  • For move-in or move-out situations

  • When a home hasn’t been professionally cleaned in a while

Unlike standard cleaning, this process targets the areas homeowners often miss.

Kitchen Deep Cleaning Checklist

The kitchen collects grease, food residue, and bacteria faster than any other room.

A proper detailed kitchen cleaning includes:

  • Degreasing stovetop, burners, and hood vent exterior

  • Cleaning behind and beside appliances (where accessible)

  • Wiping cabinet fronts, handles, and edges

  • Scrubbing backsplash grout

  • Disinfecting light switches and door handles

  • Cleaning inside microwave

  • Wiping baseboards

  • Dusting vents and air returns

  • Removing buildup from sink fixtures

These areas affect hygiene, odors, and even pest prevention.

Why Detailed Cleaning Matters for Health

Deep cleaning does more than improve appearance:

  • Reduces allergens and dust buildup

  • Helps control bacteria growth

  • Improves indoor air quality

  • Removes grease and residue that attract pests

Homes that receive periodic detailed cleanings often feel fresher and stay easier to maintain.

How Often Should a Home Be Deep Cleaned?

While maintenance cleaning may happen weekly or biweekly, deep cleaning is often recommended:

  • Every 3–6 months

  • Before starting regular service

  • After long periods without professional cleaning

Homes with pets, kids, or allergy concerns may benefit from more frequent detailed cleaning.

The Difference Between Standard and Deep Cleaning

Standard CleaningDeep Cleaning
Surface wipe-downsBuildup and detail-focused
Visible areasHidden and neglected areas
MaintenanceReset and restoration
Quick turnaroundMore time and precision

Both are important, but deep cleaning restores a home to a higher baseline.

Final Thoughts

A truly clean home is about detail, not just appearance. Regular deep cleaning keeps your space healthier, easier to maintain, and more comfortable to live in.

If you’re considering a professional service, look for providers that clearly outline what’s included — because the difference between “basic cleaning” and meticulous cleaning is in the details.

Why Professional Cleaning Has Become Essential for North Pittsburgh Homes

Tips from Cordially Clean / / January 14, 2026

Life in North Pittsburgh moves fast. Between work, family, and everything in between, keeping a home truly clean often falls to the bottom of the list. More homeowners throughout Wexford, Allison Park, Franklin Park, McCandless, Ross Township, Cranberry Township, and Pine Township are realizing that professional cleaning isn’t a luxury—it’s a practical solution for maintaining a healthier, more comfortable home.

At Cordially Clean, we believe a clean home should feel noticeably different the moment you walk in. That’s why our approach goes far beyond basic tidying. Every cleaning is detail-driven, methodical, and customized to the unique needs of your space.

What Sets Cordially Clean Apart from Standard Cleaning Services

Many cleaning companies focus on speed. We focus on results.

Our professional cleaning services are built around consistency, trust, and attention to detail. From high-touch surfaces to overlooked areas, our team follows a proven system that ensures nothing is missed—especially in kitchens and bathrooms where buildup can affect both cleanliness and health.

We regularly work with homeowners in Bradford Woods, Hampton Township, Shaler, Gibsonia, and Seven Fields, tailoring our services to everything from busy family homes to luxury residences and rental properties.

Deep Cleaning That Resets Your Home

A professional deep clean is often the starting point for a healthier living environment. Over time, dirt, grease, soap scum, and allergens accumulate in areas that routine cleaning simply can’t address.

Our deep cleaning service is ideal for:

  • First-time clients
  • Seasonal refreshes
  • Homes preparing for recurring service
  • Properties in Mars, Valencia, and Zelienople

By thoroughly cleaning baseboards, fixtures, appliances, and high-use surfaces, we restore your home to a refreshed, like-new feel and create a strong foundation for ongoing maintenance.

Reliable Recurring Cleaning for Busy Households

Recurring cleaning is one of the most effective ways to maintain a consistently clean home while freeing up valuable time. Homeowners across McCandless, Ross Township, and Cranberry Township rely on our weekly, bi-weekly, and monthly services to keep their homes effortlessly clean year-round.

With recurring service, your home never reaches the point of overwhelm. Our team becomes familiar with your space, preferences, and priorities—delivering dependable results you can count on every visit.

Move-In & Move-Out Cleaning for Stress-Free Transitions

Moving is stressful enough without worrying about cleaning. Whether you’re settling into a new home or preparing a property for its next occupants, our move-in and move-out cleaning services ensure every room is spotless and ready.

We frequently support homeowners, renters, landlords, and real estate professionals in Pine Township, Seven Fields, and Gibsonia, helping properties show better, feel fresher, and leave a lasting impression.

Health-Focused, Eco-Conscious Cleaning

A clean home should also be a safe one. That’s why Cordially Clean uses eco-friendly products whenever possible—reducing harsh chemical exposure while still delivering a powerful clean. This approach is especially important for families with children, pets, or allergies throughout Franklin Park, Bradford Woods, and Hampton Township.

By focusing on sanitation and high-touch areas, we help create a healthier indoor environment that supports your well-being.

A Cleaning Company You Can Trust

Inviting a cleaning service into your home requires trust. At Cordially Clean, professionalism, respect, and reliability are at the core of everything we do. Our clients throughout North Pittsburgh and surrounding communities choose us not just for how their homes look—but for how easy and dependable the experience is from start to finish.

Experience the Cordially Clean Difference

Whether you’re looking for a one-time deep clean, dependable recurring service, or specialized move-in/move-out cleaning, Cordially Clean is proud to serve North Pittsburgh with premium results and personal care.

If you live in Wexford, Allison Park, Franklin Park, McCandless, Cranberry Township, Ross Township, Pine Township, or nearby, now is the perfect time to experience what professional, detail-driven cleaning can do for your home.

Contact Cordially Clean today to schedule your cleaning and enjoy a home that truly feels clean—every time you walk through the door.

The Ultimate Guide to a Cleaner, Healthier Home: Tips From Cordially Clean

Tips from Cordially Clean / / November 21, 2025

A clean home is more than just something nice to look at—it plays a major role in your health, comfort, and overall well-being. At Cordially Clean, we specialize in creating spotless, stress-free spaces for busy homeowners. Whether you’re trying to keep up with weekly chores or looking for ways to maintain long-lasting cleanliness, this guide gives you professional, easy-to-follow tips.

Why a Clean Home Matters

A well-maintained home provides benefits that go far beyond appearances:

1. Better Indoor Air Quality

Dust, pet dander, and allergens build up quickly. Regular cleaning helps reduce respiratory irritation and creates a healthier indoor environment.

2. Less Stress and More Productivity

Cluttered spaces create mental clutter. A clean home promotes relaxation, focus, and a sense of control over your day.

3. Longer Life for Your Home & Belongings

Routine cleaning prevents stains, buildup, and surface damage—helping carpets, flooring, and furniture last longer.

Simple Daily Habits for a Cleaner Home

You don’t have to spend hours cleaning every day. These small habits make a big impact:

• Make your bed each morning

This instantly makes your room feel tidier and sets a productive tone for your day.

• Wipe surfaces after use

A quick wipe-down in the kitchen or bathroom prevents grime and bacteria from building up.

• Put items back where they belong

A simple decluttering routine keeps the mess from becoming overwhelming.

Deep Cleaning Tasks You Shouldn’t Skip

Even the tidiest homes need occasional deep cleaning. Here are the areas most homeowners forget:

1. Baseboards and Trim

These surfaces collect dust and scuffs and can change the look of an entire room when cleaned.

2. Light Fixtures & Ceiling Fans

Dust buildup here spreads to the rest of your home.

3. Inside Kitchen Appliances

A clean oven, microwave, and refrigerator reduce odors and improve efficiency.

4. Windows and Tracks

Clean windows let in more light and make your home feel brighter and fresher.

Why Hire a Professional Cleaning Service?

While DIY cleaning takes care of the basics, hiring a professional like Cordially Clean delivers deeper, longer-lasting results.

• Time Savings

Spend your time doing what matters most—family, work, or relaxation.

• Consistency

Your home stays clean week after week with a reliable system in place.

• Professional-Grade Products

We use high-quality supplies and equipment that remove dirt, bacteria, and allergens more effectively.

• Customized Cleaning Plans

Whether you need weekly, bi-weekly, or monthly service, we tailor our cleaning around your lifestyle.

Eco-Friendly Cleaning Matters

More homeowners are choosing green cleaning options—and for good reason. Eco-friendly products are safer for children, pets, and the planet. At Cordially Clean, we can provide natural, non-toxic cleaning solutions that still deliver powerful results.

How to Keep Your Home Cleaner Between Visits

To extend the freshness from your professional cleaning service:

  • Use doormats at every entrance
  • Run your vacuum weekly (especially if you have pets)
  • Keep microfiber cloths handy for quick dusting
  • Stay ahead of clutter by donating unused items regularly

These small efforts help maintain that just-cleaned feeling until your next appointment.

Final Thoughts

A clean home makes life easier, healthier, and happier—and you don’t have to do it alone. Cordially Clean is dedicated to providing high-quality, detail-focused home cleaning services you can trust.

If you’re ready for a cleaner home without the stress, book your cleaning today and experience the Cordially Clean difference.