Comcast Xfinity Blast! (Superfast) – 800 Mbps Internet Review

Xfinity Blast! (Superfast) has 800/20 Mbps (upload/download) and a 1.2 terabyte (TB) bandwidth cap. It’s a great plan for simultaneously running high(ish)-bandwidth tasks on 11 devices.

As a network enthusiast, I’m searching for an internet plan that provides the most value. Maybe I’ve found it. I’ll present my findings to help you determine whether you believe it’s worth the money.

To gauge this plan’s legitimacy, I’ll cover these points:

Read on. Learn more.

What Is Comcast Xfinity Blast!/Superfast Internet?

Xfinity Blast! is Xfinity’s 800 Mbps (download) and 20 Mbps (upload) internet package for customers in the Northeastern part of the US. Whereas, they use Superfast (which has the same speeds) for the rest of the states they support.

Who’s Comcast Xfinity Blast!/Superfast Best For?

This plan is best for households that want to simultaneously run at 11 low-bandwidth devices. These could include smart home devices and music playback.

You’ll also want Superfast (Blast!) if you have multiple people in your home constantly playing online games or streaming 1080p videos.

What Can You Do With 800 Mbps Download Speeds and 20 Mbps Upload Speeds?

Before diving into the details, let’s explore what you can do with this plan’s download and upload speeds [1, 2, 3, 4, 5]:

TaskDownload Speed (Mbps)Upload Speed (Mbps)
Casual Gaming (PC)30.5
Competitive Gaming5010
High-definition Audio Streaming (Lossless)20.5
*Live Streaming on Twitch720p 60 FPS: 4.5Video: 2.5–4
Audio: 1.6
Online Gaming While Streaming24.59.24 (with speed buffer)
Watching NetflixStandard Definition: 1
1080p HD: 5
4K Ultra HD: 25
Web Surfing21
Zoom Video ConferencesGroup calling 1080p: 3.8
1:1 calling 1080p: 3.8
Group calling 1080p: 3.8
1:1 calling 1080p: 3.8
**4G Voice Over Internet Protocol (VoIP)1 concurrent call: 51 concurrent call: 5
TaskDownload Speed (Mbps)Upload Speed (Mbps)
This table shows different internet speed requirements for online tasks.

* Some websites recommend having a 35–40% buffer to account for speed fluctuations.

** These speeds remain the same until you reach 50 concurrent calls. Then you’ll need 20 Mbps upload and download speeds.

Watching Movies or Series On Streaming Services (Like Netflix)

Over 20 devices could simultaneously stream movies (or series) from sites like Disney+ or Netflix. Meanwhile, others in your home could download content onto their devices for offline use without interrupting your watching experience.

Console, PC, and Cloud Gaming Plus Live Streaming

Download and upload speed doesn’t matter when it comes to casual and competitive gaming. That’s because you download and upload barely anything during matches. However, I ran into some discrepancies during my research.

First off. Latency, the distance between your computer and the host server, makes more of a difference. The distance determines how long it’ll take for the host server to receive your data packet.

Anyway, TO AN EXTENT, upload/download speed matters. You could run a literal gaming cafe if everyone only gamed online casually without running a lot of background (or patch) downloads.


Competitive gaming. The source I have linked above the table claims you need 10 Mbps upload speeds. I’ve never gamed in a competitive setting (online). Nor could I find any legitimate sources to back or refute this claim.

Don’t take this piece of advice as gospel. Just use it as something to think about when having a lot of people share a single network.

Gaming scenarios that’ll matter with download/upload speed are:

  • Background tasks while gaming: you could have over 20 devices game online while watching YouTube in the background
  • Cloud gaming: you could have a single device run a service like Shadow on 1080p
  • Live streaming: read the next paragraph

For a stable 720p 30 fps stream, you’ll want 9.24 Mbps upload speeds (buffer included) for a single user. Having a decent upload speed helps ensure that your stream won’t disconnect and that you’ll have high-quality audio and visuals.

Work From Home

Use this plan whether you have multiple people (4+) simultaneously using devices throughout your home. Or if you use a virtual private network (VPN) for work or play. VPNs can lower your internet speed by 10–20% [6].

Depending on your encryption settings and the server you choose.

If what NordVPN claims is true, then you’d lose 120 Mbps (download) and 4 Mbps (upload). That’s a hefty loss. Especially if you use bandwidth-intensive tasks.

Upload speeds aren’t the best, even if your connection isn’t suffering from any bottlenecks (e.g., congested Wi-Fi). Your daily workload shouldn’t require too much upload speed, though.

With those speeds, you can easily handle Zoom group discussions and voice-over internet protocol (VoIP).


With 800 Mbps download speeds, you could download a single 150 GB file in a little less than 27 minutes. Unless you have multiple devices simultaneously, it won’t take you too long to download a single large file.

Or multiple smaller files.

Here’s an example to consider. One avid phone user in your home has automatic app updates enabled on their phone. Another person (a gamer) decides to download a new Steam game every day. And a third person (you) wants to download a client’s 150 GB video file.

Despite the high download speeds on this plan, your 33-minute download time will change into hours. Since you have multiple devices downloading large file sizes.

If you deal with uploading and downloading files regularly, yet have multiple people who continually download stuff, I recommend upgrading to a plan with higher download speeds.

Where Is Blast!/Superfast Available?

You can only get Blast! if you’re in the Northeastern part of the United States. You can get Superfast in every other state Xfinity supports.

They offer internet services in around 40 states. Xfinity doesn’t make it clear on what cities they support. So I recommend following this link and entering your address.

They’ll tell you whether you can use them in their area. If Xfinity does offer this plan, you’ll see a search results page.

Navigate to where it says ‘Filter by’ and expand the ‘Internet Speeds’ section. From there, click ‘800 Mbps.’

Xfinity will offer Superfast or Blast! in your area if you see a result like this:

screenshot of Xfinity Offer page for the 600 Mbps internet plan.

How Much Does Comcast Xfinity Blast!/Superfast Internet Cost?

When signing up with Xfinity for the first time, you’ll pay between $50 and $60 per month. For the first 12, 24, or 36 months. Once that time passes, you’ll pay $80–94 monthly.

These prices include a $10 discount Xfinity gives you for turning on the paperless and automatic billing features.

Other fees you can expect to pay with Connect (or Performance Starter) include:

  • Data overage charge: $10 per 50 GB block of data they add to your account ($100 max)
  • Equipment rental: $14 per month
  • Unlimited Data (optional): $30 per month
  • xFi Complete (modem/router combo): $25 a month, optional, and it gives you unlimited data
  • Professional installation (optional): $89.99; you can install your modem yourself and save yourself the installation fee
  • Late bill payment fee: $10 after a two-week grace period
  • *Early Termination Fee (12-month agreement): $110; price lowers by $10 per month until the contract ends
  • *Cancellation fee (24-month agreement): $230; they’ll lower the fee by $10 each month until your 24-month contract ends

* A Comcast Xfinity team member mentioned these fees in a forum post [7]. Keep in mind that it’s a year-old post. And the fee can change at any time.

Comcast Xfinity Blast!/Superfast Features

When subscribing to Superfast (Blast!), you’ll get these goodies from Xfinity:

  • Xfinity Wi-Fi Hotspots: over a million free Wi-Fi hotspots that give you unlimited data
  • Constant Guard: Xfinity’s in-house antivirus
  • Flex 4K streaming TV box (optional): think of an Amazon TV Fire Stick
  • Voice Remote: think of an Alexa, but as a remote
  • Cloud services: 7 email addresses and 10 GB of Cloud Storage
  • 30-day money-back guarantee
  • Self-Installation Kit: essentials you’ll need to set up your Xfinity modem yourself

If you already have a smart TV, Roku, or connect your computer to your TV, you may want to pass up the Flex box. It’s another Xfinity device that you’ll have to deal with later if you switch internet providers.

All the information I’ve found says Xfinity won’t charge you a shipping fee for the Self-Installation Kit. The DIY gateway installation bundle you get when first signing up with Xfinity.

Check with Comcast Xfinity before ordering it.

Or schedule an appointment with your nearest Xfinity store and pick up the kit there.

Comcast Xfinity Blast!/Superfast Contract

Blast! And Superfast has term agreement options of 12, 24, or 36 months. If you choose a contract-less plan, you’ll have to pay more.

If you sign a contract with Xfinity, you’ll want to review the ‘Costs’ section in this post. The cancellation fees cost a pretty penny. I couldn’t find the Early Termination Fee (ETF) for the 3-year contract.

If you have a unique circumstance that causes you to abandon Xfinity, try calling them at (800) 934-6489. Only between Monday and Saturday between 7 am to 9 pm. Eastern Standard Time.

Or you can use Xfinity Assistant. It’s available 24/7.

Some situations where they should give you an EFT credit include:

  • The account holder dying
  • Forced to move because of a natural disaster
  • You restart your Comcast Xfinity subscription 90 days after canceling
  • You have to relocate because you’re on active duty in the military

Keep an eye on the word ‘credit.’ That doesn’t mean you’re getting a refund.

Comcast Xfinity Blast!/Superfast Data Cap

Blast! and Superfast have a monthly data cap of 1.2 terabytes (TB). That means once you pass 1.2 TB of data use, they’ll add blocks of 50 Gigabytes (GB). Each block they add to your account costs you an extra $10.

However, they’ll only charge you up to $100 (500 GB). Once you pass this threshold, you won’t have to pay for any other data you use.

I have good news, though (somewhat). The first month you pass their bandwidth cap, Xfinity won’t charge you. From there on, you’ll start seeing fees on your account.

You could pay an extra $30 per month for their Unlimited Data package. Or $25 for an xFi Complete gateway (modem/router combo) to get unlimited data. But I doubt you’ll need to pay more to use more data.

Hear me out.

The below chart shows you what you can do with 1.2 TB of data: 

Online ActivityHours You Can Do Each Task
Music streaming8,500
*Doing stuff on the internet2,000+
1080p video streaming350
Online gaming1,650+
4K video streaming204
**4G Voice Over Internet Protocol (VoIP)60+

This table presents what online activities you can do with 1.2 TB of data.

* They say you’d only use 15 MB per hour. What people do on the internet varies. So take this number with a grain of salt.

Are you running a call center that uses VoIP? Or do you live somewhere where everyone is continually watching 4K videos? If not, you’ll have difficulty passing Xfinity’s bandwidth cap.

In my experience, as a paranoid person, I’d log into my Xfinity account once in a while to track how much data I’ve used. You can do so by following this link.

Or you can use the Xfinity My Account app.

Blast!/Superfast vs. Other Xfinity Plans

Check out how Blast! And Superfast compare to other internet plans (price- and speed-wise) before making a decision:

Download SpeedUpload Speed
Connect/Performance Starter $20-$40/mo75 Mbps10 Mbps
Connect More/Performance$40-$60/mo.200 Mbps10 Mbps
Fast/Performance Pro$50-$60/mo.400 Mbps10 Mbps
Superfast/Blast Pro! $65-$70/mo.800 Mbps20 Mbps
Extreme Pro/Ultrafast$70-$80/mo.1000 Mbps 20 Mbps
Gigabit $80-$110/mo.1200 Mbps35 Mbps
Gigabit X2$120/mo.2000 Mbps200 Mbps
Gigabit Pro$299.95/mo.6000 Mbps6000 Mbps
*Data last updated as of post date. These offers can vary based on location and time.

This table compares download and upload speeds, along with the price for new customers and price after a year among different Xfinity plans.

* These prices include Xfinity’s $10 discount for enabling automatic payments and paperless billing. They don’t include taxes.

With Blast!, you finally escape the 10 Mbps upload speed tiers. But now you’re stuck on whether you should pay an extra $10–20 to go with Extreme Pro (Ultrafast). The extra 300 Mbps download speeds are tempting.

But don’t spend extra money unless you need the extra speed. Figure out your household’s monthly internet needs. The next section will cover recommended download and upload speeds for various tasks.

That way, you’ll have a better chance of knowing whether you need this plan.

How Comcast Xfinity Blast!/Superfast Compares to Competitors

Take a look at whether you should go with Xfinity or other internet service providers:

Provider and PlanDownload Speeds (Mbps)Upload Speeds (Mbps)*Price (New Customer)Data Cap (TB)
Verizon (500 Mbps)500500$69.99NA
Optimum (500)50035$59.99NA
Cox (Ultimate 500)50010–500$79.991.2

This table compares the prices, internet speeds, and data caps among Cox, Optimum, Xfinity, and Verizon’s 500 Mbps plans.

* These prices all have varying factors that affect their actual price. Some include taxes, discounts, installation fees, and equipment rentals.

Verizon topped this chart with symmetrical speeds, no data cap, and a reasonable price.


It only works in certain metro areas [8].

I saw a huge red flag with Cox’s upload speeds RANGING from 10 to 500. Plus, the term agreement price seems a bit high for a plan with a data cap.

You can only use Optimum in Connecticut, New Jersey, and New York.

It looks like you’re stuck with Blast! or Superfast depending on what part of the US you’re in.


Xfinity Superfast and Blast! both work great in homes with at least six devices simultaneously performing online tasks. That doesn’t require high upload speeds.

Despite having a data cap, Blast! (Superfast) offers way higher download speeds and service availability than competitors.

See whether Xfinity offers this plan in your area.

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