Milvus vs pgvector Cost in 2026

Verified as of 2026-10-18 against the official vendor pricing and documentation pages cited below.

Order the three by scale: pgvector wins at small RAG scale if Postgres is already in the stack, the Zilliz Cloud free tier (5 GB plus 2.5 million vCUs a month) covers prototyping if it is not, and self-hosting Milvus only pays off at roughly 100M-plus vectors. The headline figure most founders chase, raw managed cost, is set at small volume by free tiers and by the memory a vector index needs; the real lever is whether you already operate Postgres and how many vectors you actually have. This article prices each option on a concrete scenario with the verified rates.

1. Three deployment options, three cost shapes

• pgvector on Postgres. The pgvector extension adds vector search to a database you may already run. Cost is the Postgres tier plus storage, and the tier is set by memory, since the HNSW index answers fast when it fits in RAM; marginal cost of vectors is near zero if Postgres with spare memory is already there.
• Zilliz Cloud (managed Milvus). Fully managed Milvus with a free tier and usage-based paid plans. Zero operational burden, priced on compute units and storage.
• Self-hosted Milvus. The open-source engine on your own infrastructure. Free software, but you pay for and operate the servers, with a minimum 8 GB RAM standalone footprint^[3].

The cost shapes differ: pgvector is a database bill that steps up with index memory, Zilliz is metered compute plus storage, and self-host is infrastructure plus your operational time. The cheapest depends entirely on scale and on whether Postgres is already running.

2. pgvector total cost, computed

Scenario: 200,000 vectors at 1,536 dimensions, 2,400 queries per day, 1,500 ingests per day. The Embeddings DB Cost engine prices pgvector on Supabase Pro at the compute size that holds the index.

The engine reports the Postgres-plus-pgvector line at $125 per month: Supabase's Pro plan at $25, which includes $10 of compute credit and 8 GB of disk^[4], plus Large compute at $110^[7]. Large is the smallest size that fits, because Supabase's own pgvector benchmark held 100,000 1,536-dim vectors in Medium's 4 GB and 224,482 in Large's 8 GB^[6]. The 1.43 GB footprint, stored once in the table and once in the index, sits inside the included disk. If you already run Postgres for application data and it has that memory to spare, the marginal cost of adding pgvector is effectively zero.

3. Zilliz Cloud managed Milvus cost

Zilliz Cloud's free tier is 5 GB of storage plus 2.5 million vCUs of compute a month, with up to 5 collections^[1]. The worked scenario (200k vectors, 1.43 GB) fits inside the free tier on storage, so a prototype runs at zero cost while its monthly compute stays within the 2.5 million vCUs.

For paid usage, storage is standardized at $0.04 per GB per month from January 1, 2026 across AWS, Azure, and Google Cloud^[2]. Dedicated clusters now list per-vector rates by cluster type: from $63 per million vectors a month on performance-optimized clusters, $16 on capacity-optimized and $5 on tiered storage, measured on 768-dimension vectors^[1]. So storage is verifiable at $0.04 per GB-month, and dedicated compute has published reference rates, but a 1,536-dimension index still needs the calculator for your specific cluster.

4. Self-host Milvus: free software, real infrastructure

Milvus is free open-source software, but self-hosting carries infrastructure and operational cost. A standalone Milvus node needs at least 8 GB of RAM^[3], and a production cluster runs many components. At small scale, a single VM with 8 GB RAM might cost $30 to $50 per month, comparable to the managed alternatives but with you carrying the operations.

Self-hosting becomes clearly economical only at large scale, around 100M-plus vectors, where it can run several times cheaper than managed Zilliz. Below that, the operational burden (deploying, monitoring, upgrading a distributed system) outweighs the saving. For a solo founder, self-hosting Milvus is rarely the right first move; it is a scale optimization, not a starting point. The Build vs Buy Decision Engine prices this operational-cost trade-off.

5. The verified comparison table

Dimension	pgvector	Zilliz Cloud	Self-host Milvus
Model cost	$125/mo on Supabase at 200k vectors; near zero on existing Postgres[4]	Free tier, then metered[1]	Infrastructure only (OSS free)[3]
Free tier	Supabase free 500 MB[4]	5 GB + 2.5M vCUs/month[1]	Unlimited (you host it)
Storage rate	$0.125/GB overage (Supabase)[4]	$0.04/GB-mo from Jan 2026[2]	Your disk cost
Compute rate	Included in tier[4]	CU-hour (calculator)[1]	Min 8 GB RAM node[3]
Operational burden	Low (managed)	None (managed)	High (you operate)
Best at scale	Small, Postgres already there	Small-to-mid, no Postgres	100M-plus vectors

6. Which to pick

1. Pick pgvector if you already run Postgres with memory for the index. Marginal vector cost is near zero, and you get SQL filtering plus transactional consistency for free.
2. Pick Zilliz Cloud if you do not run Postgres and want zero operations. The free tier (5 GB plus 2.5 million vCUs a month) covers prototyping; paid storage is $0.04 per GB-month from January 2026.
3. Self-host Milvus only if you are at 100M-plus vectors and have the Kubernetes capacity to operate it. Below that scale, the saving does not cover the operational cost.

For the wider picture, the cheapest vector database ranking prices eight vendors at one scenario, and the Embeddings DB Cost calculator prices pgvector against the managed stores for your own vector count.

Frequently asked questions

Is Milvus or pgvector cheaper for a small RAG app?

At solo-founder scale, pgvector usually wins on total cost if you already run Postgres with memory to spare, where the marginal cost of adding vectors is near zero. A new Postgres sized for the index is not cheap: 200k 1,536-dim vectors need Supabase's Large compute, $125 a month all in. Zilliz Cloud (managed Milvus) has a free tier of 5 GB storage plus 2.5 million vCUs a month that covers prototyping, then a serverless or dedicated paid tier. Self-hosting Milvus is free software but needs at least 8 GB RAM and grows to $300 to $600 per month only at 100M-plus vectors, far above small-app scale.

What does Zilliz Cloud cost in 2026?

Zilliz Cloud has a free tier of 5 GB storage plus 2.5 million vCUs a month, with up to 5 collections. From January 1, 2026 storage is standardized at $0.04 per GB per month across AWS, Azure, and Google Cloud. Dedicated clusters list per-vector rates by cluster type, from $63 per million vectors a month (performance-optimized) to $16 (capacity-optimized) and $5 (tiered storage), measured on 768-dimension vectors; size other dimensions in Zilliz's calculator (checked 2026-10-18).

Is self-hosting Milvus worth it?

Only at scale. Milvus is free open-source software, but a standalone deployment needs at least 8 GB RAM, and a production cluster runs many components. Self-hosting becomes economical against managed Zilliz at roughly 100M-plus vectors, where it can be several times cheaper, but at solo-founder scale the operational burden outweighs the saving and pgvector or the Zilliz free tier is simpler.