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Keil MDK vs MongoDB Atlas

Keil MDK logo

Keil MDK

Developer Tools

Microcontroller Development Kit for Arm-based devices

From
Free
Free plan
Yes
Full reviewWebsite
MongoDB Atlas logo

MongoDB Atlas

Technology

The multi-cloud developer data platform

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: Keil MDK pricing for Essential and Professional subscriptions not disclosed on primary site; MongoDB Atlas m0 free tier limited to learning and exploration only with no backup capability
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which Keil MDK and MongoDB Atlas actually diverge.

Attributes where Keil MDK and MongoDB Atlas differ
AttributeKeil MDKMongoDB Atlas
Pricing modelfreemiumusage-based
CategoryDeveloper ToolsTechnology

Identical on both: starting price (Free), free tier (Yes), platforms (Web), user rating (Not yet rated).

What people use each for

The jobs each tool is most often brought in to do.

Keil MDK

  • Embedded software developmentnot MongoDB Atlas
  • ARM microcontroller programmingnot MongoDB Atlas
  • Professional development environmentsnot MongoDB Atlas

MongoDB Atlas

  • Building applications with flexible JSON document storagenot Keil MDK
  • Performing full-text and vector search on unstructured datanot Keil MDK
  • Scaling multi-cloud deployments across AWS, Azure, GCPnot Keil MDK
  • Streaming event data integration with Kafkanot Keil MDK

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Keil MDK

  • Pricing for Essential and Professional subscriptions not disclosed on primary site
  • Customers must contact Arm Developer Tools store for subscription rates

MongoDB Atlas

  • M0 free tier limited to learning and exploration only with no backup capability
  • Data transfer egress charges apply at 0.12 USD/GB for dedicated clusters; inbound free
  • MongoDB Search and Vector Search add significant per-hour costs starting at 0.12 USD/hour

Pricing, plan by plan

Keil MDK

Free

No published plan breakdown. See the Keil MDK review.

MongoDB Atlas

Free
  • M0 (Free Tier)Free
    • 512 MB storage
    • Shared RAM and vCPU
    • No backups
  • Flex Tier$0.011/hour
    • 5 GB storage
    • Shared RAM and vCPU
    • Pay-as-you-go hourly billing
  • M2 Shared$9/month
    • 2 GB storage
    • Shared RAM and vCPU
  • M5 Shared$25/month
    • 5 GB storage
    • Shared RAM and vCPU

Which should you pick?

Choose Keil MDK if

  • You want to start without paying.
Keil MDK review

Choose MongoDB Atlas if

  • You want to start without paying.
MongoDB Atlas review

Questions people ask

Is Keil MDK or MongoDB Atlas better?
Neither clearly leads. Keil MDK starts at Free and MongoDB Atlas at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Keil MDK or MongoDB Atlas?
Keil MDK starts at Free and MongoDB Atlas at Free.
Does Keil MDK or MongoDB Atlas run on more platforms?
Both run on Web, so platform support will not decide this one for you.
Can I use Keil MDK for free?
Both have a free tier, so you can try either at no cost before committing.
What is Keil MDK best used for?
Keil MDK is most often used for embedded software development, arm microcontroller programming, professional development environments. Of those, embedded software development and arm microcontroller programming are not what MongoDB Atlas is typically brought in for.

Answered from the vendors’ own pages

Keil MDK: Does Keil MDK have a free version?

Yes, Keil MDK Community Edition is free for non-commercial projects. Essential and Professional editions are available as monthly or annual subscriptions.

Source
MongoDB Atlas: How much does MongoDB Atlas cost?

MongoDB Atlas offers a free M0 tier with 512 MB storage, Flex tier at approximately 8-30 USD/month with pay-per-hour billing, shared clusters at 9-25 USD/month, and dedicated clusters from 56.94 USD/month. Add-on services like MongoDB Search cost 0.12-3.27 USD/hour.

Source
Keil MDK: How much do Keil MDK paid editions cost?

Specific pricing for Essential and Professional editions is not published on the main site. Rates are available from the Arm Developer Tools store or by contacting Arm sales.

Source
MongoDB Atlas: Is there a free tier?

Yes, MongoDB Atlas M0 free tier offers 512 MB storage with shared resources, suitable for learning and exploration. Flex tier allows pay-as-you-go usage starting at 0.011 USD/hour.

Source
MongoDB Atlas: What are the data transfer limits?

Inbound data transfer is typically free; egress from dedicated clusters costs 0.12 USD/GB. Free and Flex tiers do not incur data transfer charges.

Source
MongoDB Atlas: What backup options are available?

M0 free tier and Flex tier do not include backups. Dedicated clusters M10 and above include backup services with region and snapshot storage-based pricing.

Source
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