Top 7 LLM Caching Tools in 2026 (Compared Honestly)

“LLM caching” means two very different things, and most tool roundups mix them up. Response caching stores an answer and replays it when the same (or a similar) request comes back — the model never runs. Prompt caching (prefix caching) is a discount the providers themselves offer: the model runs normally, but any prompt prefix it has seen recently is billed at roughly 10% of list price.

Both save real money, but they fail differently: a response cache can return a stale or wrong answer, while a prompt cache can only ever miss — costing you the discount, never correctness. This list covers the best tools for both, and is upfront about which kind each one does. (Disclosure: Caching.ai is our product. We've kept the comparisons factual — if you spot an error, email support@caching.ai and we'll fix it.)

1. Caching.ai — make the provider's 90% discount actually land

Caching.ai is a drop-in proxy for the Anthropic, OpenAI, Gemini and Grok APIs that focuses on one job: making sure the provider-side prompt-caching discount you already qualify for actually shows up on your bill. Integration is a single base-URL swap — no code changes, streams pass through byte-for-byte.

• Cache Analytics — your real hit rate, dollars saved, and the number nobody shows you: dollars wasted on prompts that should have been cached.
• Cache Guard — automatic cache_control injection on Anthropic and cache-breaker detection (the timestamp in your system prompt that's silently costing 10x).
• Cache Warmer — provider caches expire after ~5 idle minutes; tiny low-cost pings keep the prefix warm exactly as long as it's economical.
• Measured, not promised — on a public benchmark of 10,000+ real billed calls: 67% saved on sparse support traffic, 89% on a shared-prefix batch, and on GPT-5.6 (where SDK-default traffic gets 0% prefix hits) hit rates restored to 97.8%+. Method and raw logs are open source.

Pricing is performance-based: 20% of verified net savings, with fees under $5/month waived — save nothing, pay nothing. The core is Apache-2.0 and self-hostable with one docker compose up. What it is not: a response cache, a router, or an observability suite — it does one thing deeply.

2. Helicone — observability first, caching included

Helicone is an open-source LLM observability platform: request logging, cost tracking per user and feature, sessions, prompt experiments. Its caching feature is exact-match response caching configured with request headers — repeat an identical request and the stored response comes back instantly and free. If your primary need is seeing what your LLM app is doing, Helicone is a strong pick, and the cache is a nice bonus for identical repeats (think test suites and demo traffic). It does not manage provider prefix caches. See our detailed Caching.ai vs Helicone comparison.

3. Portkey — the kitchen-sink AI gateway

Portkey is a full-featured AI gateway: routing across hundreds of models, retries and fallbacks, guardrails, a prompt library, observability — plus both simple (exact) and semantic response caching with per-route TTLs. If you want one hosted control plane for many LLM concerns, Portkey covers the most ground of anything on this list. The trade-off is surface area: more concepts to configure, and the caching is response-level — the provider-side prefix discount is still up to you. Detailed comparison: Caching.ai vs Portkey.

4. LiteLLM — one API for 100+ providers

LiteLLM is the de-facto open-source standard for provider unification: an OpenAI-format proxy in front of 100+ providers, with load balancing, budgets, and virtual keys. Caching is Redis-backed response caching (with an optional semantic mode). If your problem is “we call six providers and want one interface with spend controls,” LiteLLM is excellent. Its cache dedupes identical requests; it doesn't warm or protect provider prefix caches. The two proxies also chain cleanly — details in Caching.ai vs LiteLLM.

5. Cloudflare AI Gateway — caching at the edge

Cloudflare's AI Gateway sits at the edge in front of your provider and adds logging, analytics, rate limiting, retries, and exact-match response caching with a TTL. It's free at its core, trivially easy to try (swap the base URL), and great operational insurance. Caching-wise it's the same story as the other gateways: identical requests hit, everything else misses, and prefix economics are out of scope.

6. GPTCache — DIY semantic caching

GPTCache (from Zilliz) is the best-known open-source semantic cache library: it embeds each query, stores responses in a vector store, and returns a cached answer when a new query is similar enough. Powerful when you have high volumes of near-duplicate questions and tolerance for approximate answers — FAQ bots are the classic case. Be aware it's a library you operate yourself (embedding model, vector store, similarity threshold are all your problem), and development activity has slowed. Background reading: prompt caching vs semantic caching.

7. Provider-native prompt caching — the baseline everyone should use

Anthropic, OpenAI, Gemini and Grok all ship prefix caching natively: Anthropic via explicit cache_control breakpoints (reads at ~10% of input price), OpenAI automatically for stable 1,024+ token prefixes, Gemini with implicit caching plus explicit context caches, Grok automatically. It's not a tool you install — it's the discount all the tools above sit on top of. The catch, and the reason this list exists: caches expire in minutes, unstable prefixes break matching silently, and none of the providers show you the hit rate you're losing. Start here, then add tooling when the bill justifies it. Full mechanics: What is prompt caching?

How to choose

• Your bill is dominated by repeated prompt prefixes (agents, chatbots, RAG with big system prompts): maximize prompt caching — that's Caching.ai or careful DIY.
• You serve many identical or near-identical requests: add a response cache — Helicone, Portkey, LiteLLM or Cloudflare AI Gateway.
• You need multi-provider routing and spend controls: LiteLLM (OSS) or Portkey (hosted).
• You mainly need visibility: Helicone.
• Not sure where your money goes? Measure first — a proxy that shows hit rate and wasted spend turns the rest of this list from guesswork into arithmetic.