Analyzing 6,465,7806.5M ReviewsFor 17,96018K Experts
We graded 10 companies on seven things customers actually report: satisfaction, reliability, workmanship, value, momentum, track record and how owners handle complaints.
From 11,442 Google reviews of 33 top-rated commercial cleaning services nationwide; 10 of them in Corona, CA. Updated November 1, 2026.
Pick the job — we re-rank companies by how customers rated that exact job.
Experts Score 0–100Experts Score (0–100)Absolute quality first: recency-weighted star average (≈54%), share of 1–2★ reviews (≈24%), customers’ price verdicts (≈14%), owner replies to critical reviews (≈7%); minus up to 10 points each for complaints flagged in Google review highlights and for a real slide in recent ratings. Hover a company’s score on its page for the full breakdown. and a letter grade per factor (A = top 20% of commercial cleaning services).
| # | Company | ScoreExperts Score (0–100)Absolute quality first: recency-weighted star average (≈54%), share of 1–2★ reviews (≈24%), customers’ price verdicts (≈14%), owner replies to critical reviews (≈7%); minus up to 10 points each for complaints flagged in Google review highlights and for a real slide in recent ratings. Hover a company’s score on its page for the full breakdown. | FactorsFactor grades, in orderSatisfaction (54%): Recency-weighted star average (2-year half-life), shrunk toward the category mean by review volume; the company’s own lifetime average as the prior; absolute: 4.0★ = 0, 5★ = 100.Reliability (24%): How rarely jobs go badly: share of 1–2★ reviews — 60% the last 24 months (or the 20 newest if fewer), 40% all-time; 0% = 100, 15%+ = 0; the category percentile can only raise it.Craft & service (0%): Google review highlights: Quality, Professionalism, Responsiveness, Punctuality — how rarely reviewers flag them as a negative, per review since highlights began; 0% = 100, 5%+ = 0. Subtracted from the score (up to −10), never averaged in — clean highlights are the norm, not a bonus.Value (14%): Customers’ own price verdicts (Great / Reasonable vs Overpriced) and Value highlights; 65% absolute (all “reasonable” ≈ 80, “great” = 100), the category percentile can only raise it.Momentum (0%): Penalises only a real slide: last-12-month average below lifetime (−0.5★ = 0). Still 4.8★+ over the last year, or steady/improving = 100. Subtracted from the score (up to −10), never averaged in.Replies to reviews (7%): How often the owner publicly replies to reviews under 5★ (1–4★). Needs 3+ such reviews, otherwise not counted; 65% absolute (80%+ replied = 100), the category percentile can only raise it.One letter per factor score: A = 80+, B = 60–79, C = 40–59, D = 20–39, F = below 20. | ★Google star rating as shown on Google Maps. | Typical billMedian bill customers of this company reported in their reviews (needs 3+ priced reviews). |
|---|---|---|---|---|---|
| 1 |  Sunshine Janitorial ServiceCorona, CA | A 98How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 69%99+68.5Reliability 31%96+29.5Experts Score= 98Not enough data for value, replies to reviews; its weight is shared by the others.Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AA––A– | 5.00 | — |
| 2 |  Like Never Before Janitorial Services, Inc.Corona, CA | A 97How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 59%98+57.5Reliability 26%97+25.3Value 15%97+14.8Craft & service penalty99−0.1Experts Score= 97Not enough data for replies to reviews; its weight is shared by the others.Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAA– | 5.00 | — |
| 3 |  City Wide Facility Solutions - Inland EmpireCorona, CA | A 96How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 64%95+60.4Reliability 28%97+27.4Replies to reviews 8%96+7.9Experts Score= 96Not enough data for value; its weight is shared by the others.Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AA––AA | 4.94 | — |
| 4 |  Aria Commercial Cleaning ServicesCorona, CA | A 96How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 59%98+57.5Reliability 26%96+25Value 15%87+13.2Craft & service penalty98−0.2Experts Score= 96Not enough data for replies to reviews; its weight is shared by the others.Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAA– | 5.00 | — |
| 5 |  All Purpose Janitorial ServiceCorona, CA | A 95How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 69%94+65.1Reliability 31%97+29.8Experts Score= 95Not enough data for value, replies to reviews; its weight is shared by the others.Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AA––A– | 4.95 | — |
| 6 |  Smart JanitorialCorona, CA | A 89How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%91+49.6Reliability 24%90+21.8Value 14%100+14.1Replies to reviews 7%54+3.8Craft & service penalty99−0.1Experts Score= 89Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAC | 4.85 | $424 |
| 7 |  Junic CleaningCorona, CA | A 88How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%90+49.1Reliability 24%97+23.5Value 14%100+14.1Replies to reviews 7%16+1.1Experts Score= 88Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAF | 4.90 | $350 |
| 8 |  Icleaning Services LLCCorona, CA | A 87How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 64%89+56.5Reliability 28%81+22.9Replies to reviews 8%96+7.9Experts Score= 87Not enough data for value; its weight is shared by the others.Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AA––AA | 4.90 | — |
| 9 |  CCS LLCCorona, CA | A 83How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%88+48Reliability 24%79+19.2Value 14%88+12.4Replies to reviews 7%86+6.1Momentum penalty76−2.4Experts Score= 83Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | ABAABA | 4.91 | $309 |
| 10 | Three Star Janitorial WarehouseCorona, CA | B 75How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 64%83+52.7Reliability 28%77+21.7Replies to reviews 8%13+1.1Experts Score= 75Not enough data for value; its weight is shared by the others.Grade B: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AB––AF | 4.75 | — |
What customers paid, from the price Google asks reviewers to report.
| Job | Low25th percentile: 1 in 4 customers paid less than this. | TypicalMedian of the bill customers reported in their Google review (Google asks reviewers for a price range; we use the middle of each range). | High75th percentile: 1 in 4 customers paid more than this. | FairOf customers who rated the price, the share who chose “Great price” or “Reasonable” rather than “Overpriced”. |
|---|---|---|---|---|
| General carpet cleaning | $139 | $176 | $279 | 99% |
| Standard cleaning | $164 | $203 | $259 | 98% |
| Deep clean | $309 | $371 | $490 | 97% |
| Carpet steam cleaning | $164 | $214 | $298 | 100% |
| Upholstery cleaning | $139 | $180 | $266 | 100% |
| Moving-related cleaning | $321 | $384 | $467 | 97% |
How the 10 commercial cleaning services we rated in Corona, CA compare, and what customers praise most.
A = score 80+, F = below 20.
Average stars per company.
Share of Google review highlights.
All price verdicts left with reviews.
Share calling it great / reasonable / overpriced.
Satisfaction (54%) — Recency-weighted star average (2-year half-life), shrunk toward the category mean by review volume; the company’s own lifetime average as the prior; absolute: 4.0★ = 0, 5★ = 100.
Reliability (24%) — How rarely jobs go badly: share of 1–2★ reviews — 60% the last 24 months (or the 20 newest if fewer), 40% all-time; 0% = 100, 15%+ = 0; the category percentile can only raise it.
Craft & service (penalty, up to −10) — Google review highlights: Quality, Professionalism, Responsiveness, Punctuality — how rarely reviewers flag them as a negative, per review since highlights began; 0% = 100, 5%+ = 0. Subtracted from the score (up to −10), never averaged in — clean highlights are the norm, not a bonus.
Value (14%) — Customers’ own price verdicts (Great / Reasonable vs Overpriced) and Value highlights; 65% absolute (all “reasonable” ≈ 80, “great” = 100), the category percentile can only raise it.
Momentum (penalty, up to −10) — Penalises only a real slide: last-12-month average below lifetime (−0.5★ = 0). Still 4.8★+ over the last year, or steady/improving = 100. Subtracted from the score (up to −10), never averaged in.
Replies to reviews (7%) — How often the owner publicly replies to reviews under 5★ (1–4★). Needs 3+ such reviews, otherwise not counted; 65% absolute (80%+ replied = 100), the category percentile can only raise it.
The 10 best-rated commercial cleaning services in Corona, CA average 4.9★ on Google across 1,024 reviews. Like Never Before Janitorial Services, Inc. has the top rating (5.0★), and Junic Cleaning has the most reviews (295). Updated October 29, 2026.
10 companies that meet our bar: rated 4.5★ or higher on Google, with a meaningful review history (1,024 reviews combined) and currently operating. Request a call back and the company will phone you directly.
“They did a fantastic job cleaning my house. Great communication they showed up exactly when they are supposed to and did a great job. I was out of town and they sent my pictures. Very professional company and I would…” — Google review
“Was in need of a move out clean for my mom’s place. Scheduling the service was very easy and efficient! The cleaner arrived and cleaned well. My mom had 4 cats and after she finished cleaning, I could not smell the…” — Google review
“We have received excellent service from Like Never Before Services for many years now. They do an excellent job and keep our office in good condition and their rates are very reasonable. We are very happy with their…” — Google review
“Un lugar perfecto para los que buscas tener productos muy buena y exelente precio el servcio con mi amigo Jaime y chris 10 de 10” — Google review
“We’ve been using Icleaning Services for daily office cleaning at our location in Corona, and we’ve been very pleased with the service. The company is reliable, professional, and consistently keeps our offices clean…” — Google review
“Since the day I reached out to All purpose janitorial Eric has been very responsive and helpful. We have use this company for about 2months now and we have had no complaints about his team. Very nice personal. Prices…” — Google review
“Best service we’ve received! I’m so glad we changed our janitorial vendor. Angie in sales was understanding, efficient, and truly on point. She worked within our budget and made the entire process easy. I’m extremely…” — Google review
“Had a great experience with this cleaning company! The staff is friendly and hard working. We had some very dirty windows, screens and tracks cleaned-they are now sparkling clean! We also had the carpet cleaned-they…” — Google review
“Quick and friendly service! We have Terrazzo floors and once a year we get floor cleaning. The floors look so good, clean and refreshed.” — Google review
“I’ve had a great experience with Smart Janitorial. Shout out to Issac, our account representative, who has been great to work with and is always easy to communicate with. He’s responsive, helpful, and makes the…” — Google review
We scan Google Maps for commercial cleaning service listings in and around Corona, keep only open businesses whose main category matches the service, and require a Google rating of at least 4.5 from at least 20 reviews. Companies are ordered by a confidence-weighted score that balances rating and review volume. We do not accept payment for placement.
Like Never Before Janitorial Services, Inc. has the highest Google rating on our Corona list: 5.0 out of 5 from 48 reviews (as of October 29, 2026).
Junic Cleaning has the most Google reviews among the companies listed here: 295, with a 4.9★ average.
Only open Corona-area businesses whose Google category matches the service, rated at least 4.5★ from at least 20 Google reviews. They are ordered by a confidence-weighted score of rating and review volume. Placement is never paid.
Also in Corona: Dumpster Rental Services
Analyzing 6,465,7806.5M ReviewsFor 17,96018K Experts