PostgreSQL vs MySQL: Which Should Your SaaS Use? (2026)

The Night I Almost Chose MySQL

In 2023, deep into building Clickly — my Bitly-style URL shortener that I over-engineered into oblivion — I hit a fork in the road that a lot of founders hit. Postgres or MySQL?

I already had PostgreSQL running. It was fine. It was more than fine. But I made the classic broke-engineer mistake: I went looking for a reason to switch. Every big scaling war story I’d ever read — YouTube, Facebook, Uber in the early days — ran on MySQL. And here I was, a guy with zero users, convinced I needed whatever the billion-user apps used. So I spent a couple of nights reading MySQL sharding blog posts at 1 AM, feeling like I was about to unlock some secret the Postgres crowd didn’t know about.

Spoiler: I wasn’t. I stayed on Postgres. And in the years since, having gone down the full advanced database rabbit hole — ClickHouse, Timescale, Turso, the works — I’ve never once regretted it.

But “just use Postgres” is a lazy answer if I don’t tell you why, and when it’s wrong. So this is the head-to-head. If you searched “PostgreSQL vs MySQL” because you’re staring at that same fork, this is me sitting next to you at 1 AM telling you which way to go. (And if you’re a step earlier — not sure how SQL the language even relates to MySQL the database — start with SQL vs MySQL.)

---

The Only Honest Starting Point

Let me get the verdict out of the way, because I hate posts that make you scroll for it.

For roughly 99% of the SaaS products you’ll ever build, use PostgreSQL. Full stop.

That’s not tribalism. Both databases are relational, both are ACID-compliant, both speak SQL, both are open-source and free, both have been in production for nearly three decades, and both will happily power a company worth a billion dollars. If you flipped a coin and picked MySQL, your SaaS would probably be fine. Nobody churns because you chose the wrong database engine.

So why do I still say Postgres without blinking? Because when the two are this close on the fundamentals, you decide on the edges — the extensions, the JSON handling, the ecosystem, the ownership, and where you’ll actually run the thing for free. And on almost every one of those edges, Postgres is the safer bet for a solopreneur who can’t afford to migrate later.

---

Where They’re Basically Twins

Don’t let comparison blogs scare you into thinking these are wildly different beasts. For your first 10,000 users, they overlap almost completely:

• Both handle relational data, joins, transactions, and foreign keys properly.
• Both do replication, backups, and point-in-time recovery through their managed hosts.
• Both have mature drivers for every language and every ORM — Prisma, Drizzle, whatever you like.
• Both are genuinely fast enough that your code will be the bottleneck long before the database is.

If someone tells you MySQL is “faster,” ask them faster at what. For simple, read-heavy lookups — the kind a login system or a settings page does — MySQL has historically been a touch quicker out of the box. For complex queries, concurrent writes, and anything analytical, Postgres tends to pull ahead. For your SaaS, this difference is noise. You will not feel it.

So the tie-breakers live elsewhere.

---

Where Postgres Quietly Runs Away With It

Here’s where the coin stops being fair.

JSON. Modern SaaS stores a lot of semi-structured data — settings blobs, webhook payloads, API responses you don’t want to fully normalize. Postgres has jsonb, a binary JSON type you can index with GIN and query with real operators (@>, ?, and friends). MySQL has a JSON type too, but you can’t index it directly — you extract values into generated columns first, which is fiddlier. In head-to-head tests, Postgres JSON queries come back roughly 3–4x faster than MySQL’s. If your app leans on JSON at all, this alone settles it.

Extensions. This is the real moat. Postgres has 300+ extensions, and two of them matter enormously in 2026:

• pgvector — vector search for AI features, right inside your existing database. If you’re bolting a RAG chatbot or semantic search onto your SaaS, this is a one-line install. MySQL 9 added a basic vector type, but it’s nowhere near as mature.
• PostGIS — the gold standard for geospatial queries. If you ever do anything with maps, radius search, or “find stores near me,” nothing in the MySQL world comes close.

Add Timescale for time-series and you get a database that morphs into whatever you need without you switching providers. For a solopreneur, “no migration later” is worth more than any benchmark.

Standards and data types. Postgres is stricter about SQL correctness and ships richer native types — arrays, ranges, proper booleans, real enums. MySQL has quietly forgiven bad data for years (its historical loose handling of invalid dates and silent truncation is legendary), and while modern strict mode fixes most of it, Postgres never made you opt in to correctness in the first place.

---

MySQL’s Real Edge (It’s Not Nothing)

I’m not here to dunk on MySQL. It powers a shocking amount of the internet, and it has one genuine superpower Postgres can’t casually match: battle-tested horizontal scaling.

The story is worth knowing. YouTube’s MySQL databases were buckling under scale, so their engineers built Vitess — an open-source layer that shards MySQL horizontally across many machines. Those same engineers later left and founded PlanetScale. Their customer list is a who’s-who of companies operating at a scale you and I will probably never touch, and the product gives you read replicas, bare-metal performance, and no cold starts.

If you know — not hope, know — that you’re building something that needs to shard across dozens of nodes from day one, the MySQL + Vitess lineage is real, proven, and hard to replicate in Postgres-land. MySQL’s replication has also simply been in production longer, so the operational playbooks are deeper.

But read that sentence again: if you know. Almost none of us know that on day one. We think we do — I certainly did at 1 AM in 2023 — and then we ship to twelve users. Choosing MySQL for a scale you don’t have yet is the database equivalent of buying a race car to drive to the grocery store.

---

Who Actually Owns These Things

This part matters more than people admit, and it’s where the two diverge hardest.

PostgreSQL is owned by nobody. It’s developed by a global community, the PostgreSQL Global Development Group. There’s no company that can wake up one morning, get acquired, and change the license out from under you. That’s not a small comfort when you’re betting a business on it. The current stable release is PostgreSQL 18, with 19 already in beta as of mid-2026 — steady, boring, dependable progress.

MySQL is owned by Oracle. It landed there in 2009 when Oracle bought Sun Microsystems (which had bought MySQL). Oracle keeps MySQL alive and shipping — 8.4 is the current long-term-support (LTS) line, with a faster-moving 9.x “Innovation” series for newer features — but it’s a single, very commercial company steering a product it also competes with. Some people are perfectly fine with that. Others got nervous enough in 2009 to do something about it — which is the whole MariaDB vs MySQL fork story, if you want MySQL without the Oracle part. (There’s a third managed option too — Microsoft’s SQL Server as Azure SQL Database — but its pricing is a DTU-vs-vCore maze a founder can happily skip.)

Which brings us to the fork. When Oracle took over, MySQL’s original creator Michael “Monty” Widenius forked it into MariaDB, precisely so the open-source community wouldn’t be at one company’s mercy. It’s stewarded by the non-profit MariaDB Foundation and stays largely drop-in compatible with MySQL. If you love MySQL’s model but distrust Oracle’s ownership, MariaDB is the honest answer — though for a new SaaS, I still wouldn’t start here over Postgres.

---

The Part That Actually Decides It: Where You’ll Run It

Databases don’t live on your laptop. They live on a managed host, and for a broke founder, the hosting economics settle the whole debate.

For Postgres, Neon (now a Databricks company) gives you a genuinely usable free tier with autoscaling and pause-on-idle, so a quiet database costs you almost nothing. I’ve run seven Postgres databases on Neon for $0 for years. Supabase is the batteries-included alternative if you want auth and storage bundled in — I compared the serverless Postgres options here.

For MySQL, the flagship managed home is PlanetScale — and here’s the catch. PlanetScale has no free tier anymore. They killed the Hobby plan back in 2024. Today the cheapest way in is a single-node Postgres database at $5/month, with production HA clusters starting at $15 and their bare-metal “Metal” tier at $50. And yes, you read that right — in 2025 PlanetScale launched managed Postgres too, which tells you something about which way the wind is blowing.

So the practical math for a founder with $0 MRR is brutal and simple: Postgres lets you start for free and scale without switching providers. MySQL’s best home charges you from day one. When you’re counting paisa before your product earns a rupee, that’s not a tie-breaker — it’s the whole game.

---

When MySQL Actually Wins

Let me be fair and give you the honest list. Reach for MySQL (or MariaDB, or PlanetScale/Vitess) when:

1. You’re inheriting it. An existing codebase, a team that knows it cold, a client’s stack. Don’t rewrite a working thing to satisfy a blog post.
2. You genuinely need Vitess-grade horizontal sharding and you can prove the scale is real, not aspirational.
3. Your hosting or platform is MySQL-native and fighting it costs more than it’s worth.
4. A specific tool you depend on is built MySQL-first. Rare in 2026, but it happens.

Notice what’s not on that list: “because big companies use it,” or “because I heard it’s faster.” Those were my reasons in 2023, and they were bad ones.

---

The Bottom Line

If you’re building a normal SaaS in 2026 and you searched this to settle an argument in your own head: pick PostgreSQL, run it on Neon, and go build your actual product. You get better JSON, the pgvector and PostGIS extensions when you need them, no single corporate owner, and a free tier that lets you survive the long $0-MRR winter. That combination is why every deeper guide on this site quietly lands in the same place.

MySQL isn’t wrong. It’s excellent, it’s everywhere, and PlanetScale’s engineering is genuinely beautiful. But it wins in the specific, high-scale corners — not in the messy, broke, “please just work and stay free” middle where the rest of us actually live.

I spent three weeks and a few sleepless nights learning this the expensive way. You just read it in nine minutes. Don’t be like 2023-me, hunting for a reason to switch off the thing that was already working.

This is the Broken Engineer Guide — I over-engineer everything, fail at business, and hand you the shortcuts so you don’t have to bleed for them. Now close the tab and go ship.