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Amazon DynamoDB uses custom pricing as of May 2026. Contact Amazon DynamoDB directly for a personalized quote. Pricing depends on your chosen tier, contract length, and negotiated discounts.

Use the interactive pricing calculator to estimate your exact cost based on team size and requirements.

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+70% above list price
Know Before You Buy — Try Amazon DynamoDB Free

Amazon DynamoDB uses custom pricing and true cost runs 70% above the quoted price as of May 2026. Contact the vendor for a quote. Hidden costs like implementation and support add significantly to the total. Key hidden costs: batch write unit misunderstanding, on-demand vs. provisioned pricing gap, per-table throughput over-provisioning. Verified from 1 sources by CostBench.

Hidden Costs Breakdown

1

Batch Write Unit Misunderstanding

critical overage

DynamoDB charges per item (row) written, not per API call. A BatchWriteItem call with 25 items costs 25 write request units — not 1. This misunderstanding is one of the most common causes of massive unexpected bills, with developers reporting $5,000–$8,000 charges from single bulk data load operations.

hn

I just spent 8k USD on writing 2 billion rows to two tables because I misunderstood how Dynamo charges for write units. I thought I was going to spend a few hundred (still a lot, but our bill is big anyway) because I'm doing batch write requests of 25 items per call. But the dynamodb pricing doesn't care about API calls, it cares about rows written, or write capacity units, or something.

reddit

I misunderstood pricing for dynamodb writes. I thought a single batch write of 25 items would cost one write unit. It costs 25 write units. Think I spent about 5k USD.

2

On-Demand vs. Provisioned Pricing Gap

high overage

For identical throughput, on-demand pricing can cost up to 7x more than provisioned capacity when tables run at sustained load. On-demand is cost-effective only when utilization stays below approximately 14% of the provisioned equivalent. Teams with steady traffic who choose on-demand for operational simplicity frequently overpay by hundreds of dollars per month.

reddit

Suppose I have a table with 1,000 read units and 100 write units, that table would cost me $94.90/mth on provisioned pricing while on on-demand it would cost $657.00/mth. This is 7 times more expensive, which works out such that if I utilise the table less than 14% of the time, but still kept the provisioned capacity at maximum, then on-demand would be cheaper.

hn

The downside of on-demand is the pricing - it's more expensive if you have continuous load. But it can easily become _much_ cheaper if you have naturally spiky load patterns.

3

Per-Table Throughput Over-Provisioning

high overage

In provisioned capacity mode, throughput must be configured per table individually. Teams pay for the maximum expected throughput on every table at all times, even when tables are rarely accessed simultaneously. Adding new tables increases costs even if aggregate traffic stays flat. Downgrading provisioned capacity is limited to once per day.

hn

You have to provision throughput for each table individually, so you basically have to pay for the maximum throughput you expect for every single table all the time (you can only reduce your throughput once per day as far as I understand). This means that adding a new table can be pretty expensive (even if your total throughput isn't increasing at all).

4

Large Item Size Write Cost Multiplier

medium overage

DynamoDB charges 1 write unit per 1 KB (or fraction thereof). Writing a 50 KB item — such as a rich text notes field or a document — costs 50 write units, not 1. Teams must provision for the full item size at all times, multiplying both provisioned capacity costs and on-demand write charges proportionally to average item size.

hn

Each unit of throughput gives you one 1kb write/read per second. If you exceed your throughput for a second, the call fails. This means that if you want to support the ability to write 50kb (like a "notes" field or something), you need to constantly pay for 50 write units even if you won't ever realistically use that much.

5

Scan Operation Costs

high overage

DynamoDB does not support SQL JOINs. Queries without a proper partition key result in full table scans, consuming read units for every item in the table regardless of how many results match the filter. Teams that don't design access patterns upfront often discover expensive scans after deployment, consuming orders of magnitude more read capacity than targeted key lookups.

reddit

DynamoDB is a great database, super easy to operate and very consistently performant, but you're gonna have a hard time if you don't know what data access patterns you need (since there are no joins and scans are outrageously expensive).

hn

DynamoDB's pricing scales sublinearly with volume; if it starts getting expensive it was an initial misuse of DynamoDB that got obvious with scale.

6

Global Secondary Index Write Amplification

medium overage

Every Global Secondary Index (GSI) on a DynamoDB table requires additional write capacity units for each write to the base table. A table with 5 GSIs can multiply effective write costs by 6x (1 base + 5 GSIs). Teams adding GSIs to support filter and sort requirements often discover this cost amplification only when bills arrive.

reddit

WCU cost scales with the number of GSIs

7

Scale-Up Cost Cliff

high overage

DynamoDB's linear pricing model means costs grow directly with throughput. At small scale the service is cheap, but at sustained production volumes, costs can become higher than self-managed alternatives (Cassandra, PostgreSQL) including their operational overhead. Multiple engineering teams have documented switching to self-hosted databases when DynamoDB costs exceeded the cost of running their own infrastructure.

hn

DynamoDB is the most expensive one. For small datasets with low RPS it provides a lot of value, but once you scale, it becomes cheaper to run ourselves (even including licensing costs). I blame their linear pricing model.

hn

the pricing schemes on these services are designed to hook you with affordable prices in the beginning, but later on as your business grows they get much more expensive than hosting your own stuff. So use whatever makes you most productive, but careful about lock-in.

8

Connected AWS Service Cost Amplification

medium addon

DynamoDB costs are rarely isolated. API Gateway, Lambda authorizers, and CloudWatch logging each add charges per request on top of DynamoDB. At high volumes, API Gateway alone can cost 3–4x more than DynamoDB and Lambda combined. Teams often budget for DynamoDB in isolation without accounting for the full cost of the surrounding AWS service stack.

reddit

API Gateway's pricing might also be a bit of a shocker, so double check the pricing for your estimated volumes. At high volumes, it can be 3-4x what you are paying for DynamoDB/Lambda.

reddit

each query also triggered your authorizer Lambda which has invocation fees. Then, each API call also writes data to CloudWatch twice: once for your GrahpQL logging, and then again the authorizer Lambda which writes it invocation logs. And finally, your DynamoDB rakes up costs for read/write operations. So now you look at a bill which is a multitude higher than the seemingly cheap AppSync services suggests on its pricing page.

Example: True Cost for 25 Users

License (custom pricing) Contact vendor
Batch Write Unit Misunderstanding +$1,000-$10,000
On-Demand vs. Provisioned Pricing Gap +50-600% of license costs
Per-Table Throughput Over-Provisioning +15-50% of license costs
Large Item Size Write Cost Multiplier +10-50% of license costs
Scan Operation Costs +20-100% of license costs
Global Secondary Index Write Amplification +20-500% of license costs
Scale-Up Cost Cliff +10-50% of license costs
Connected AWS Service Cost Amplification +100-400% of license costs
Estimated Year 1 Total Contact vendor
That's roughly 1.7× the advertised license price. The median Amazon DynamoDB contract is $25/yr across 4 Vendr purchases.

Frequently Asked Questions

01 What hidden costs should I budget for with Amazon DynamoDB?

Beyond the license fee, budget for: Batch Write Unit Misunderstanding ($1,000-$10,000); On-Demand vs. Provisioned Pricing Gap (50-600% of license costs); Per-Table Throughput Over-Provisioning (15-50% of license costs); Large Item Size Write Cost Multiplier (10-50% of license costs); Scan Operation Costs (20-100% of license costs); Global Secondary Index Write Amplification (20-500% of license costs); Scale-Up Cost Cliff (10-50% of license costs); Connected AWS Service Cost Amplification (100-400% of license costs). Total ownership typically runs 70% higher than the listed price.

02 Does Amazon DynamoDB charge for implementation?

Implementation costs for Amazon DynamoDB vary by deployment size and customization. Contact the vendor or check our sourced hidden-cost breakdown above for verified figures.

03 How much does Amazon DynamoDB support cost?

Premium support pricing for Amazon DynamoDB depends on your tier and contract terms. See the sourced cost breakdown above for any verified figures we have.

04 Are there overage or storage costs with Amazon DynamoDB?

DynamoDB charges per item (row) written, not per API call. A BatchWriteItem call with 25 items costs 25 write request units — not 1. Estimated impact: $1,000-$10,000.

05 What add-ons cost extra with Amazon DynamoDB?

Add-on pricing for Amazon DynamoDB varies by feature. The sourced cost breakdown above lists any verified add-on costs we have.

Now You Know the Real Cost — Try Amazon DynamoDB Free