Ky vs Axios: 9.8 KB vs 19.6 KB Gzip

I bundled the browser HTTP clients on this box: ky 2.1.0 came in at 9,777 B gzip against axios 1.20.0 at 19,559 B. On a localhost JSON GET loop, ky sat at about 365 us per request and axios at about 269 us.

Short answer: pick ky when you want a Fetch-based client at about half the gzip weight. Pick axios when you need broad adapters, upload progress, or the older XHR path. No affiliate links in this post.

What I tested

• Machine: 8 vCPU Intel Xeon / 15 GB RAM shared Linux cloud box, tested 6 Oct 2026 about 01:01–01:02 IST.
• Versions: ky 2.1.0, axios 1.20.0, Node 22.20.0 (built-in fetch), esbuild 0.28.2 minify + gzip -9.
• Fixture: /workspace/bench-ky-axios/. Browser size: ky.get(url).json() vs axios.get(url).then(r => r.data). Also ky.create() and axios.create(). Speed: local http.Server returning a 32-byte JSON body; 500 sequential GETs × 9 rounds (median) after warm.
• Findings: gzip 9,777 B vs 19,559 B for the simple get helpers; create wrappers 9,817 B vs 19,598 B. Median loop 182.714 ms vs 134.455 ms for 500 requests (about 365 vs 269 us/req; 2,737 vs 3,719 req/s). Disk trees about 720 KB vs 2.2 MB.
• One surprise: axios was faster on this sequential localhost JSON path even while shipping about 2× the gzip. The size win for ky is clear; the raw Node loop is not.
• Not tested: browser XHR path, upload progress, interceptors under load, retries/timeouts at scale, React Query / SWR wrappers, HTTPS, HTTP/2, or FormData multipart.

How wide was the size gap?

Browser build (esbuild minify)	Minified	gzip -9
ky.get().json()	28,589 B	9,777 B
axios.get().then	51,098 B	19,559 B
ky.create()	28,682 B	9,817 B
axios.create()	51,187 B	19,598 B

ky was about 2.0× smaller gzip on both the one-shot and create entries. Track shipped weight with size-limit vs bundlesize. Mock the same clients in tests with msw vs nock.

How fast were the localhost GETs?

Path (500 sequential JSON GETs, median of 9)	ky	axios
Local http.Server, 32-byte body	182.714 ms (365 us/req)	134.455 ms (269 us/req)

On this box axios completed the sequential loop about 1.36× faster. That does not erase a ~10 KB gzip gap on the browser build. Request harness notes sit next to my Jest vs Vitest write-up when I pull these clients into a test runner.

Which one should you pick?

Situation	My pick
Browser app on Fetch, watch the gzip budget	ky
Need axios interceptors / upload progress / older Node	axios
New greenfield Fetch-first client	ky
Migrating a large axios codebase	stay on axios unless size is the blocker
Bundle budget under about 12 KB gzip for HTTP	ky

Bottom line: ky 2.1.0 shipped 9.8 KB gzip against axios 1.20.0 at 19.6 KB, while axios won the sequential localhost JSON loop (269 vs 365 us/req). Who should not switch: teams already deep in axios adapters and interceptors — rewrite cost beats a 10 KB gzip win if size is not the constraint. Validate payloads with Zod vs Valibot. Unused-export cleanup: knip vs depcheck.

How this was made: I installed ky and axios on the ShopperCove box, measured esbuild minify+gzip browser sizes, timed sequential localhost JSON GETs, and recorded the JSON. The write-up was drafted with AI help and checked against that output.

Sources

• https://github.com/sindresorhus/ky
• https://www.npmjs.com/package/ky
• https://github.com/axios/axios
• https://www.npmjs.com/package/axios

Related

• https://www.shoppercove.com/blog/size-limit-vs-bundlesize
• https://www.shoppercove.com/blog/msw-vs-nock
• https://www.shoppercove.com/blog/jest-vs-vitest
• https://www.shoppercove.com/blog/knip-vs-depcheck
• https://www.shoppercove.com/blog/zod-vs-valibot
• https://www.shoppercove.com/blog/ajv-vs-zod
• https://www.shoppercove.com/blog/biome-vs-eslint-prettier
• https://www.shoppercove.com/blog/oxlint-vs-eslint