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Developer Tools · head to head

Keil MDK vs Unit21

Keil MDK logo

Keil MDK

Developer Tools

Microcontroller Development Kit for Arm-based devices

From
Free
Free plan
Yes
Full reviewWebsite
Unit21 logo

Unit21

Cybersecurity

No-code fraud and AML risk operations platform for fintechs and neobanks

From
On request
Free plan
No
Full reviewWebsite

The short version

  • Only Keil MDK has a free tier, so it costs nothing to try first.
  • Each has a real cost: Keil MDK pricing for Essential and Professional subscriptions not disclosed on primary site; Unit21 it is built for fintech scale rather than card issuer scale, so organisations reaching very high transaction volumes generally re-evaluate against heavier platforms and face a migration.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Keil MDK and Unit21 actually diverge.

Attributes where Keil MDK and Unit21 differ
AttributeKeil MDKUnit21
Starting priceFreeOn request
Pricing modelfreemiumquote
Free tierYesNo
CategoryDeveloper ToolsCybersecurity

Identical on both: platforms (Web), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Keil MDK

Nothing recorded that Unit21 does not also cover.

Only in Unit21

  • No-code rule builder
  • Case management
  • SAR filing
  • Backtesting
  • Identity and device signals
  • Data ingestion API

What people use each for

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

Keil MDK

  • Embedded software developmentnot Unit21
  • ARM microcontroller programmingnot Unit21
  • Professional development environmentsnot Unit21

Unit21

  • A neobank whose sponsor bank requires a documented monitoring programme before it will keep the BIN sponsorshipnot Keil MDK
  • A crypto exchange needing SAR filing and case management without building an internal compliance engineering teamnot Keil MDK
  • A payments startup where the fraud lead needs to ship a new rule the same day a new attack pattern appearsnot Keil MDK
  • A lender consolidating fraud alerts from three point tools into one investigator queue with a single audit trailnot 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

Unit21

  • It is built for fintech scale rather than card issuer scale, so organisations reaching very high transaction volumes generally re-evaluate against heavier platforms and face a migration.
  • No-code rule authoring shifts power to the risk team, which is the point, but without governance it produces rule sprawl that nobody can explain to an examiner two years later.
  • Detection quality depends on the signals you feed it, so a thin integration produces thin results and the platform cannot compensate with proprietary consortium data the way larger vendors do.
  • Pricing is quoted by volume with an annual commitment, so a fintech whose growth stalls pays for headroom it did not use.
  • SAR filing coverage is oriented to United States FinCEN reporting, so firms filing in the United Kingdom, European Union or Asia handle those submissions outside the tool.

Pricing, plan by plan

Keil MDK

Free

No published plan breakdown. See the Keil MDK review.

Unit21

On request
  • Unit21 Platform$undefined/year
    • Priced by monitored volume and modules, annual contract
    • Fraud, AML and case management packaged separately
    • Implementation and historical data backfill quoted with the subscription

Which should you pick?

Choose Keil MDK if

  • You want to start without paying.
Keil MDK review

Choose Unit21 if

  • You need no-code rule builder.
  • You also want case management.
Unit21 review

Questions people ask

Is Keil MDK or Unit21 better?
Neither clearly leads. Keil MDK starts at Free and Unit21 at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Keil MDK or Unit21?
Keil MDK has a free tier; the other does not. Paid plans start at Free for Keil MDK and On request for Unit21.
Does Keil MDK or Unit21 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?
Yes. Keil MDK has a free tier, so you can try it without paying. Unit21 starts at On request.
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 Unit21 is typically brought in for.
What can Keil MDK do that Unit21 cannot?
Unit21 covers No-code rule builder, Case management, SAR filing, Backtesting.

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
Unit21: Do we need engineers to run it?

Only for the initial data integration. After that the design intent is that risk and compliance staff author and deploy rules themselves.

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
Unit21: Does it file SARs?

Yes, it generates and electronically files suspicious activity reports to FinCEN. Non-US regimes are not covered to the same depth.

Unit21: Can we test a rule before it goes live?

Yes. Backtesting against historical data to see projected alert volume is one of the more useful parts of the product, because alert volume is the real cost.

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