Deno vs. Node.js vs. Bun: Performance Comparison 2025

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► I’m a Senior Software Engineer at Juniper Networks (13+ years of experience)
► Located in San Francisco Bay Area, CA (US citizen)

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▬▬▬▬▬▬▬ Timestamps ⏰ ▬▬▬▬▬▬▬
0:00 Intro
0:42 1st Test - Static
4:26 2nd Test - PostgreSQL

▬▬▬▬▬▬▬ Source Code 📚 ▬▬▬▬▬▬▬

#deno #bun #nodejs

[jarredsumner]

The memory usage you're seeing in Bun.SQL is a bug. We have a fix.

(original comment seems to have been removed probably because I linked to the PR fixing it)

[ulrich-tonmoy]

Node - V8 & written in c++ and js
Deno - V8 & written in rust
Bun - JSC & written in zig

[this.tushar]

Bun is improving every day. I hope we see more of this kind of competition in the tech industry, as it leads to better products and an enhanced dx. The more competitors, the better the outcome for consumers

[zginversion]

Thanks 🙏 very nice! Bit disappointed with Deno, but perhaps they can squeeze some more out in the future. Would be interesting to compare Deno concurrency with Go 😊

[piotrbielski]

Great video! We are still missing on of the most popular techonologies on your list - JVM. Would be nice to see how JVM optimisations compare to .NET or raw performance of Go. Thank you for this series!!

[DavidSmith-efeh]

Dat bun memory usage in second test. You probably discovered a memory leak :D

[dami-i]

I see the Bun memory usage going up and think to myself: "oh my... the next AWS invoice..."

[lorenzogrv]

Excelent benchmark, like everyone I've seen at your channel. Definitely I was waiting your comp between theese three engines. I did expect some metric, but other are... Interesting 😅. Thx and keep up the good work 🎉❤

[LucasRC]

Great job. I've recently started to watch this channel, and it is so interesting to understand these benchmarks before creating even small projects. I really understand this work you do as valuable even for new developers such as me, so BIG THANKS.

Small correction:
you said, Bun is based on Zig, Deno is based on Rust and Node is based on the V8 Engine

That's technically true, but not really

Both Node and Deno are based on Google's V8 Engine, while Bun is based on Apple's JavascriptCore
So not only Node is based on V8.

Node itself is written in C++, but Deno is indeed written in Rust, and Bun in Zig

[snnsnn]

People keep saying Bun is written in Zig but that is not entirely true. Parts of it is written in zig but JavaScript runtime is JavaScriptCore (JSC) that is what powers webkit, which is written in C++. Networking and HTTP handling are built on uSockets, a C++ library. Not fully spec compiant yet, AFAIK. Some lower-level parts use C for interoperability. Bun is a mix of Zig, C++, and C, optimized for speed and efficiency. Deno is not written in Rust. Event loop and the glue code is in Rust but runtime is v8, which is c++. Node is also a mix. Libuv v8 etc etc.

[canerkuru]

Can you compare web socket services as well? maybe NodeJS, Bun and Go?

[SimDom]

Now, Bun vs. Go vs. Java (Quarkus) is a fine benchmarking test to witness.

[BleedingDev]

Would love to see comparison between ElysiaJS, HonoJS and EffectTS HttpAPI/RPC. 😍

PS: You do a great job, love that I found your channel!

[omak]

Great! After a while, you can make a new performance measurement. For example, when the new major versions will be released.

[zakimimit]

I hope the next video:
*Bun 1.2 with (hono vs elysia vs fastify)

[rayyanep]

cool video as always! was wondering if you have any plans to do a video on cloudflare in the future

[almostprofessionalrecords]

Is the memory leak in Bun & PostgreSQL already reported? If not, could you report it to the Bun team?

[igors]

Would be interesting to see Bun vs Go metrics as they could be very close.

[navarro]

I would definitely like to see this one
NGINX Unit PHP vs NGINX + PHP-FPM vs Apache + PHP-FPM