Quick answer
Aiven - Aiven wins for most builders who want a truly no-card, always-free database or Kafka sandbox, while Koyeb wins if you need to run apps or APIs alongside a broader serverless platform.
How the free tiers compare
These free tiers solve different problems. Aiven is narrower but cleaner: it gives you always-free managed PostgreSQL, MySQL, Kafka, and OpenSearch with no credit card, and the free services sit on the same managed infrastructure as paid plans. That makes it a good fit when you mainly need a database or message/search backend and want to keep it alive without a trial clock. Koyeb is broader and more application-oriented. Its free tier bundles compute credit, serverless Postgres, bandwidth, domains, deployments, and observability, so it is better when you want to deploy a working service, not just a datastore. The tradeoff is that Koyeb requires a card, and its free value is expressed through credits and limits rather than always-free standalone services. After free, Aiven’s next step is cheap and flat at $5/mo; Koyeb’s paid path starts at $29/mo plus compute, so the step-up is much steeper.
Aiven vs Koyeb free tier, side by side
| AivenFTV 59 | KoyebFTV 40 | |
|---|---|---|
| Credit card requiredOnly state this because Aiven and Koyeb explicitly provide the field. | No | Yes |
| Always freeAiven says no trial expiry; Koyeb’s free tier is a capped credit-based offer. | Yes | No |
| PostgreSQL free storageKoyeb’s free Postgres also includes 0.25 vCPU and 1 GB RAM. | 1GB | 1 GB |
| MySQL free storageKoyeb’s free tier includes Postgres, not MySQL. | 1GB | Not offered in the free tier |
| Kafka free limitKoyeb does not list Kafka in its free tier. | 250 kb/s in and out, retention up to 3 days | Not offered in the free tier |
| OpenSearch free storageKoyeb does not list OpenSearch in its free tier. | 20GB | Not offered in the free tier |
| Custom domainsKoyeb includes 10 custom domains on the free tier. | Not listed | 10 |
| BandwidthAiven notes network costs on free databases; Koyeb publishes 1 TB/month included. | Network costs apply | 1 TB per month |
| Deployments / computeKoyeb’s free tier is centered on running services and compute. | Not included | Included |
After you outgrow the free tier
Aiven is mostly flat-priced after free: the first paid tier is Developer at $5/mo, then a sales-led platform tier. That makes its cost curve simple and cheap if you just need a managed database. Koyeb uses a flat platform fee plus usage-based compute, starting at $29/mo + compute on Pro and $299/mo + compute on Scale. That means small apps can stay manageable, but the base fee is much higher than Aiven’s. For typical small-team database use, Aiven is cheaper; for app hosting, Koyeb’s costs scale with runtime usage and plan level.
Cost at real usage
| Usage | Aiven | Koyeb |
|---|---|---|
| Light database-only projectKoyeb’s Pro plan adds included compute credit but still has a $29 base fee. | $5/mo on Developer tier, or Free if the free limits are enough | $29/mo +compute on Pro |
| Small team app with one backend serviceAiven does not provide app hosting in the input, so this is only a database-side comparison. | $5/mo if only using Aiven-managed Postgres/MySQL | $29/mo +compute |
| Need team features and more service headroomAiven’s platform tier is sales-led; Koyeb publishes Scale pricing. | Contact sales | $299/mo +compute on Scale |
Estimates, not quotes. Usage-based rates change - verify with the vendor's pricing page before committing.
When to pick each one
Pick Aiven when…
- You need a managed PostgreSQL, MySQL, Kafka, or OpenSearch instance for a side project or prototype.
- You want a free tier that does not expire and does not require a credit card.
- You only need one service of each type and single-node is enough.
- You want to test the same managed stack you might later pay for, without changing platforms.
- You care more about database and messaging backends than about deploying full applications.
Pick Koyeb when…
- You want to deploy an API, web app, or inference workload, not just a database.
- You need built-in bandwidth, custom domains, logs, metrics, and deployment tooling in one place.
- You expect to use multiple services and users, even on the free tier.
- You are okay with a card requirement and a credit-based free allowance.
- You may grow into a platform plan with team features, regional deployment, and app hosting controls.
Bottom line
For the most common builder case, Aiven is the better free-tier pick if your immediate need is a database, Kafka, or search backend that can stay on without a card. Koyeb is the better pick if you are trying to run an actual application and want compute, domains, deploy tools, and observability in the same free bundle. The price jump after free is also gentler on Aiven, so database-first builders are likely to stay happier there.
Read the full listings: Aiven and Koyeb. Scores use the FTV methodology at /ftv. Browse more head-to-heads on /compare, or see the top-ranked free tiers on /top.