Bun vs Node.js vs Deno -- UK JavaScript Runtime (2026)

Updated: June 20269 min read
UKGBPComparisonUK GDPRUK Law

Node.js 20 LTS is ClickMasters default for all UK regulated production workloads: largest ecosystem (npm -- every NHS, FCA, and GDS library available), longest-term LTS support (critical for NHS DTAC evidence continuity), and the most proven regulated-sector production track record. Bun is ClickMasters default for development speed (Bun dev server and test runner in development -- faster feedback loops). Deno is right for secure-by-default scripts and edge workloads. Runtime choice affects NHS DTAC Domain 3 security patch availability, FCA PS21/3 LTS support continuity, and UK developer talent market availability.

FactorNode.js 20 LTSBun 1.xDeno 2.x
NHS DTAC LTS support (3+ years)BEST -- Node.js 20 LTS until April 2026, Node.js 22 LTS from Oct 2024No formal LTS -- Bun updates frequentlyDeno LTS in progress -- less mature LTS model
FCA PS21/3 security patchesBEST -- Node.js CVE patches within 7 days (Dependabot)Bun patches frequent -- less formal CVE trackingDeno security patches -- improving
npm ecosystem compatibilityBEST -- every NHS/FCA/GDS npm package works95% npm compat -- some native modules failnpm compatibility improving but gaps remain
Development speed (tests, bundling)Good -- Jest + esbuildBEST -- Bun test runner 10x faster than Jest, native bundlerGood -- Deno built-in test runner
UK developer talent poolBEST -- Node.js universally knownGrowing -- Bun gaining tractionSmall -- Deno niche
TypeScript nativeVia ts-node or tsx (< 1 second compile)BEST -- TypeScript native, zero configBEST -- TypeScript native, zero config
AWS Lambda supportBEST -- Node.js 20 Lambda runtime (AWS managed)Bun on Lambda (custom runtime -- not AWS managed)Deno on Lambda (custom runtime -- not AWS managed)
ECS Fargate (Docker)BEST -- official Node.js Docker images, well-testedOfficial Bun Docker image -- goodOfficial Deno Docker image -- good
ClickMasters defaultAll UK regulated production (NHS, FCA, GDS)Development speed (dev server, test runner, scripts)Secure scripts, edge workloads, Deno Deploy

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