Sonic vs OpenSearch
Both are alternatives to Algolia. Here's how they stack up — verified facts, no spin.
Also searched as OpenSearch vs Sonic — same comparison, one verdict.
Sonic and OpenSearch are closely matched on ownership (94 vs 91) — this one comes down to pricing and to which trade-offs below you can live with.
Sonic
A search index in about 30 MB of RAM, when you need less than you think.
Sonic is a deliberately minimal Rust search index: it stores identifiers rather than documents, so you query Sonic for matching IDs and fetch the actual records from your own database. That design keeps memory in the tens of megabytes where a conventional engine wants gigabytes, and it makes Sonic a serious option for small services, edge deployments and anything running on hardware you would not consider adequate for search. MPL-2.0, around 21.3k stars. It is not trying to be Algolia — it has no faceting and no relevance tuning — and being clear about that is the point of listing it.
OpenSearch
The Apache-2.0 Elasticsearch fork — when search is only half the job.
OpenSearch is the fork AWS created after Elastic changed Elasticsearch's licence in 2021, kept under Apache-2.0 and now governed by a foundation. It is far more than a search box: aggregations, analytics, log ingestion, dashboards and vector search in one platform, which is exactly right if search and observability are the same infrastructure problem for you and exactly wrong if you only wanted a fast product search. Around 13.4k stars. It is the heaviest option here and it earns that weight only when you need what it does.
Side by side
10 points of comparison, every one read from a verified field. Green marks the side that wins a row outright. A dash means we do not hold that fact — never that it is zero.
| Sonic | OpenSearch | |
|---|---|---|
| Sovereignty ScoreOur transparent 0–100 composite for data ownership and exit cost. | 94 | 91 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first data | Yes | Yes |
| License | MPL-2.0 | Apache-2.0 |
| Pricing | Free and open source. Runs in around 30 MB of RAM. | Free and open source. Managed OpenSearch is available from AWS and others. |
| RAM to run it wellThe figure that actually matters, not the vendor's minimum. | — | 8 GB heap on a 16 GB machine |
| Realistic running costWhat the box costs each month if you run it yourself. | — | $60–120/mo for a small cluster, against Algolia pricing that bills per search operation |
| Setup timeHonest first-install estimate, not the marketing quickstart. | — | Half a day for one node, a week for a production cluster |
| Ongoing maintenanceThe part nobody budgets for. | — | Real. Shard sizing, JVM heap and index lifecycle are all yours. |
Sonic edges it on the Sovereignty Score, but the right pick depends on the trade-offs below.
Weighing both against staying on Algolia? Is Algolia free? What it actually costs →
Sonic
Strengths
- +Extraordinarily light — tens of megabytes rather than gigabytes
- +Fast enough for most real workloads despite the footprint
- +MPL-2.0, simple to deploy, almost nothing to operate
- +Ideal for edge, embedded and small-service deployments
Trade-offs
- −Returns identifiers only — you fetch the documents yourself
- −No faceting, no aggregations, no relevance tuning
- −Minimal ecosystem and few integrations
- −Wrong tool if search is a core product surface
OpenSearch
Strengths
- +Apache-2.0 under foundation governance — the licence question is settled
- +Handles search, analytics, logs and vectors in one platform
- +Enormous ecosystem inherited from Elasticsearch
- +Managed offerings exist if you would rather not operate a cluster
Trade-offs
- −Substantially heavier than the purpose-built search engines
- −JVM tuning and cluster operation are a real skill set
- −Relevance needs meaningful configuration to match Algolia
- −Overkill if all you need is a fast search box
Which one fits you
The trade-offs above, turned into a decision. Find the line that describes your team.
Choose Sonic
if a lower exit cost matters more to you than any single feature, and extraordinarily light — tens of megabytes rather than gigabytes.
Choose OpenSearch
if apache-2.0 under foundation governance — the licence question is settled.
Neither, yet
if both carry a real cost you should weigh first — returns identifiers only — you fetch the documents yourself, and substantially heavier than the purpose-built search engines. If either of those is a dealbreaker for your team, the shortlist is wrong rather than the choice.
What it takes to run these yourself
Real requirements and honest running costs, not the vendor quickstart.
Sonic vs OpenSearch — common questions
Is Sonic a better fit than OpenSearch for search infrastructure?
It depends on what you are optimising for, and the honest split is this: Sonic scores 94 to OpenSearch's 91 on data ownership and exit cost, so it is the safer choice if you care about being able to leave. OpenSearch earns its place on a different axis — apache-2.0 under foundation governance — the licence question is settled. Neither is a wrong answer for every team; the table above is the actual comparison.
What happens if we want to switch later?
Sonic keeps its data local or in open formats, so leaving is an export rather than a negotiation. OpenSearch is still self-hostable, so the files stay on your server either way — but it is not local-first by design, so check what its export produces before you rely on it.
Can I self-host Sonic or OpenSearch?
Both can be self-hosted. The difference is what it costs you in time rather than whether it is possible — see the setup and maintenance rows above.
Are Sonic and OpenSearch both alternatives to Algolia?
Yes — both appear in our Algolia comparison, which is why they are worth putting side by side. People usually arrive here already having decided to move off Algolia and now choosing between the two replacements, which is a narrower and much easier question.
Related alternative guides
Facts verified 2026-07-31. Licenses and pricing change — spotted something out of date? That's a correction we want.