Have an Iridium handset or Go, Fleet One, Pilot, Certus 100/200/700 or other low bandwidth and/or high cost/MB satellite connection?  Wanting to find a way to access the web with that connection?  While a slow satellite connection won’t grant you access to the entire web, there are certainly ways to get access to some parts of the web.  Read on for more information on low-bandwidth web browsing.

What is “Low Bandwidth”?

Based on our testing, the standard world wide web — sites such as Facebook, CNN, Twitter, Amazon, etc — is generally unusable at data speeds below about 300kbps.  Media streaming sites of course require more bandwidth and while Youtube can work okay at speeds under 1mbps (1024kbps), most other streaming services, including video conferencing apps like Zoom, require more than 1mbps of bandwidth.  For all of the non-VSAT satellite terminals on the market today, all are under 1mbps in speed, and all of them have data costs generally above $1/MB.  For this reason we will define low bandwidth as any non-VSAT satellite terminal.   You can certainly browse much of the web with a Fleet Broadband 250 or higher, but the cost of data will add up quick, so it’s still useful to know how to access as much as you can with as minimal data usage as possible.

Network data speeds for common non-VSAT satellite terminals

Time to download 1MB file
Iridium Narrowband
Iridium 9555/9575/Go

Sailor SC4000
Redport Glow/Aurora
(yes, 2 point 4)
~ 1 Hour
Iridium Certus 100
Lars Thrane LT-4100
Iridium Go! Exec
88kbps download
22kbps upload
~ 1.5 Minutes
Iridium OpenPort/Pilot132kbps~ 1 Minute
Inmarsat Fleet One150kbps~ 1 Minute
Iridium Certus 200
Thales Vesselink 200
176kbps~45 Seconds
Inmarsat FBB250284kbps~ 30 Seconds
Inmarsat FBB500432kbps~ 20 Seconds
Iridium Certus 700
Thales Vesselink 700
Intellian C700
Cobham Sailor 4300
704kbps download
up to 352kbps upload
~12 Seconds

Bits or Bytes?

Note: The size of a file is generally measured in bytes, kilobytes (KB), megabytes (MB), or gigabytes(GB).  The bandwidth (speed) of a data connection is generally measured in bits per second (bps), kilobites per second (kbps), megabits per second (mbps), and gigabits per second (gbps).  There are 8 bits in a byte.  kbps = kilobits per second, mbps = megabits per second.  Technically since most data measurements are made based on base-2 numbering, we also use 1024 instead of 1000 for these increments, it seems that most software and services have moved to using 1000, and designated the name for base 2 as kibobit vs kilobit.  In practice, the difference between using base-2 and base-10 is minimal so we will just use base-10 for this discussion.  Also, while many people get this wrong, the accepted proper practice is to use capital B for Bytes and lower case b for bits.


  • 1 gbps = 1000 mbps
  • 1 mbps = 1000 kbps
  • 1 kbps = 1000 bits per second

File Sizes

  • 1 GB = 1000 MB
  • 1 MB = 1000 KB
  • 1 KB = 1000 Bytes
  • 1 Byte = 8 bits

Use Low-Bandwidth Versions of Web Sites

Use low-bandwidth versions of websites you frequent.  This will save bandwidth and speed up page loading on slower networks.   The amount of data used is DRASTICALLY LOWER in the case of Gmail and Facebook when you use the low-bandwidth sites.   Loading the standard Gmail inbox consumes over 6MB of data, before you even open a specific email, and it continues consuming data forever even if yo Your order has been canceledu don’t click anything. The same view in the light version of Gmail consumes under 1MB, and only consumes additional data when you actively click on something.  Examples below.   These links are also listed on Sea-Tech’s low-bandwidth home page, where more links will be added as we find them.

News Sources

Certain news organizations manage low bandwidth text sites.  Using these can save tons of data compared with the normal websites.


Web Email and Social Media

low-bandwidth facebookFacebook Lite:  https://mbasic.facebook.com

Gmail HTML light:https://mail.google.com/mail/u/0/h/  (note: if you are logged in to multiple google accounts, the 0 in the URL can be changed to 1, 2, etc to access the other email accounts you are logged in to.)

CruisersEmail Webmail: http://seatechreg.gmn-usa.com/webmail

low-bandwidth gmailXgate Webmail: http://webmail.gmn-usa.com/

Note: If you use Gmail HTML Light or Facebook in combination with Images Disabled (see below) in your browser, they uses very little data.  But you may find Facebook less useful without the images.


Optimizing General Web Browsing: (possibly suitable for speeds of 70kbps and higher)

Block ads and flash

Use an adblocker and a flashcontrol plugin for your web browser to disable flash apps and ads that consume extra bandwidth.

chrome adblockAdblock for Google Chrome: https://getadblock.com/en/

Flashcontrol for Google Chrome (search chrome webstore for “Flash Control”)

Set your browsers’ home page to blank or use Sea-Tech’s low-bandwidth home page (https://seatech.systems/satellitehomepage.html) (less than 2KB) to reduce the amount of data your browser uses when you first launch it.  Our low-bandwidth home page has links to low-bandwidth versions of Gmail, Facebook, CruisersEmail webmail, NOAA weather, CNN, and NPR.

Limit Automatic Multimedia Downloads

Disabling web media auto-play:

Internet Explorer:
  • Play Animations = Off
  • Play Sounds in Web Pages = Off
  • Show Pictures = Off
    • (you may need to enable for some pages)



Disable auto-play: Safari -> Preferences -> Websites -> Autoplay

safari auto-play


To disable Auto-Play:

chrome autoplay policy

Launch Chrome and in the Address Bar type: chrome://flags/#autoplay-policy and hit Enter.   Change the policy to “Document User Activation…” and then restart chrome.


Disabling images until you need them:


Enable the Develop menu in Safari -> Preferences -> Advanced

safari enable develop menu

Now you can disable and reenable images easily from the Develop menu as needed.

safari disable images


To control image loading easily, install the Block Images plug-in for Chrome

Chrome Block Images Plug-In  chrome no image

Once installed you can click the icon in the chrome task bar to enable or disable images as needed.


Internet Explorer:

You can disable and enable images in the Advanced settings for the browser, but it’s not convenient if you need to enable and disable periodically for different websites.  You can also disable Active content the same way, which will block *some* videos and content from auto-playing, but it’s hit or miss.

Microsoft Edge:

There does not appear to be a setting for disabling Images in Microsoft Edge yet and no option for installing plug-ins to add functionality.

Wrap Up

Using the techniques above you can optimize your browsing experience to make it possible to access some of the web through a slow satellite connection.  With the low bandwidth sites you can gain quick access to a few sites even on very slow connections.   If you need access to normal sites over a slow connection you can use the browser optimizations to help reduce the data download sizes, saving time and money.

Look for a future post on both hardware, software, and add-on services that can control data usage in various ways, which can further help you take the best advantage of a low-bandwidth connection.

Want to Learn More about Offshore Comms?  Subscribe to Marine Electronics Advisor today and get started!

Subscribe Now!

Are you looking for a budget-friendly satellite terminal that will give you access to Whatsapp, Facebook Messenger, and iMessage text messaging plus fast Predictwind downloads and access to more email options than traditional cruiser solutions?  Take a look at our Fleet One Unlimited Americas package!