Comparisons · Cursor vs Windsurf · July 2026
Cursor vs Windsurf: which AI editor understands more of your code?
Both market the same promise ("it understands your codebase") and both deliver, for exactly one codebase: the folder you opened. Put them on the same real machine (4.47 million files, a dozen repos that ship together, plus the ~90% of the disk that was never in git) and the interesting question stops being Cursor vs Windsurf. It becomes: how much of your actual machine can either one see? The measured answer is a small, bright box on a very dark field.
TL;DR · the short version
Cursor and Windsurf are AI code editors: both forks of VS Code that build a searchable index of the project folder you open, so an agent can answer "where do we handle refunds?" without you naming the file. The difference that actually decides how much they understand is not intelligence. It is scope.
Each editor's index scope, side by side
Same machine, drawn twice. How much does each one light up?
"Understanding your codebase" is really a question of scope. Here is the same disk twice: once as Cursor sees it, once as Windsurf sees it. Each editor lights the one project you opened and indexes it well. Everything drawn dashed and dark (the sibling repos, the configs, the documents, the downloads) is invisible to that editor, because it was never inside the folder you pointed it at.
The two lit boxes are the same size for a reason: on scope, Cursor and Windsurf land in the same place. The honest read is the acid frame: the field around both boxes is the whole machine, and it belongs to neither editor. Reflects each tool's public documentation and default behavior as of July 2026; both ship far more than scope, which is not what this picture measures. See how Cursor builds its index for the mechanism, drawn fairly.
Point for point
So which one understands your codebase?
| What we're measuring | Cursor | Windsurf |
|---|---|---|
| Core product | AI-first code editor (a VS Code fork) | Agentic IDE by Codeium (a VS Code fork) |
| How it reads your code | Semantic index of the workspace you open | Codebase index its Cascade agent retrieves from |
| Retrieval method | Embeddings / vector search | Semantic retrieval over your code |
| Where the heavy index lives | Embeddings on Cursor's cloud, vectors stored remotely | Local codebase index (its context engine) |
| Multi-folder workspace | Yes, add folders | Yes, add folders |
| Freshness | On re-index / sync | As it indexes your edits |
| Sees repos you didn't open | No | No |
| Sees non-git files outside the workspace | No | No |
| Queryable by other agents (Claude Code, Codex) | No | No |
| Runs fully offline | No | No |
The fair answer: for the project you have open, they are neck and neck. Cursor leans on cloud-stored embeddings and a change-tracker that re-embeds only what you edit; Windsurf leans on a local codebase index its Cascade agent retrieves from as it works. Prefer one interface over the other, and you will be happy; this isn't a knock on either.
But look at the last four rows, in red. They agree. Neither sees the repos you didn't open, neither sees the non-git files around them, neither can be queried by a different agent, and neither runs fully offline. Those are not Cursor quirks or Windsurf quirks: they are the same ceiling every in-editor index shares, because each was built for one project at a time. The footnote below the table applies: specifics vary by plan and settings, and both offer team and enterprise options beyond the defaults compared here.
Same ceiling, two logos
Shared by Cursor, Windsurf, and every in-editor index, because each is built for one project at a time.
1 · The workspace boundary.
An index that understands "the workspace" understands exactly the folders you added. But your machine isn't one project: it's a dozen repos that ship together, plus the 90% of the disk that was never in git: configs, documents, downloads, the design PDF with the answer in it. A folder can be a collection of separate repos that ship as one product, a relationship neither Cursor nor Windsurf can hold, because each only ever looks at the projects it was pointed at. Searching across every repo at once →
2 · The index is locked in the editor.
Cursor's index answers to Cursor; Windsurf's answers to Windsurf. Switch to Claude Code, Codex or Copilot and none of that work carries over: the new agent starts from a blank directory listing and has to rediscover the machine by hand. That rediscovery has a measured price: watched end to end, an agent with no machine-wide index spent 6 minutes 57 seconds and 71 tool calls hunting one file (long enough to make a coffee) that a whole-machine lookup returns in 16 milliseconds and a single call. Why finding is the real bottleneck →
Not a third editor. The floor under both
The layer that fills the whole field. Locally, in microseconds.
Interlinked draws the acid frame in the diagram. It keeps an always-fresh index of every file on the machine (names and contents, across every repo and all the non-git files an in-editor index never sees) and exposes it to whatever agent you use through one connector. It isn't a semantic index and doesn't try to be: it is the fast, literal, exhaustive layer that answers "does this exact thing exist anywhere on this machine?" in the time Cursor or Windsurf take to notice you pressed a key. Different job, complementary to the embeddings: the floor the meaning-index stands on. Measured on a Ryzen 9 9950X3D with 4.47 million files.
Every edge is a receipt you can check (counts and hashes, never a model's guess) keyed to each file's identity on disk, so it survives a rename and belongs to no vendor. That is the fact a workspace index structurally cannot hold: that two folders in two repos are the same product. Not RAG, not memory: the layer under both →
For context on the same machine: that filename lookup takes VS Code's own search about 35 seconds (412,000× slower) and Windows Search a median 67 seconds (~480,000×). At rest the whole engine sits around 44 MB in Task Manager (less than a single browser tab) and the index on disk stays under 1% of the drive. One signed install wires it into 19 AI clients, Cursor and Windsurf included, and it never leaves the machine, with no model anywhere in the box.
NOT A REPLACEMENT FOR CURSOR OR WINDSURF. THE LITERAL, WHOLE-MACHINE LAYER UNDER BOTH, AND EVERY OTHER AGENT.
Questions people actually ask
Cursor, Windsurf, and the machine under both.
Do this today
Keep your editor. Give it a floor.
Install once. One signed installer configures 19 AI clients: Cursor, Windsurf, Claude Code, Codex, Copilot, Cline and the rest. No JSON editing, no per-tool setup, no cloud account.
Ask across everything. When you don't know which repo a thing lives in (or whether it's in a repo at all) search the whole machine and get the answer in microseconds, not a re-index wait.
Scope when you know. Point a query at one folder when you already know where you are; scoped lookups still return in the microsecond range.
Let the vault grow. Day one it knows your git history across every repo. Every week after, it knows your machine a little better, automatically, with no model in the loop.
Everything local is free forever, on all your devices, no card. Hosting starts at $5.99/mo. Download for Windows.
All Interlinked numbers measured on a Ryzen 9 9950X3D · 64 GB DDR5 · NVMe · Windows 11 · 4.47M files. More method in the 412,000× VS Code write-up and the ripgrep comparison.