Free browser-based curl comparator and curl comparison tool. Paste two curl commands side by side and see a structured diff of HTTP method, URL (base + query parameters), headers, auth, cookies, body, and common flags—plus a Monaco side-by-side diff and a raw line diff when parsing is partial or you need the full command text. Same curl parser as Spoold’s curl → code converter. Nothing is uploaded; comparison runs client-side.
Live tool: spoold.com/tools/http/curl/compare
- What this tool is for
- Who searches for this (keywords)
- Features
- How to use
- Local storage & history
- Parser & limits
- Related tools
- Tech stack & privacy
- Repository
Use this online curl diff when you need to:
- Compare curl commands from docs vs DevTools, staging vs production, or two API versions without eyeballing long one-liners.
- Spot differences in Authorization, query strings, headers, JSON bodies (pretty-printed line diff when both bodies parse as JSON), and curl flags (
-L,-k,--compressed, etc.). - Debug HTTP requests as text: see what changed in both structured tables and a full raw diff.
- Iterate quickly with swap, samples, clear, and optional document history in the app.
It is part of Spoold — developer utilities in the browser.
This README and the live page target searches such as:
Core intent: curl comparator, curl comparison tool, curl command comparator, curl compare, curl compare online, compare curl commands, curl diff, diff curl requests, two curl commands, side by side curl
HTTP / API: http request compare, compare http requests, curl request diff, api request diff, diff curl, compare curl
| Area | What you get |
|---|---|
| Dual editor | Monaco DiffEditor (shell) for curl A vs curl B; edit and paste on both sides. |
| Structured comparison | When both sides parse: method, URL split into base and query (when the URL is valid), headers (union of keys), body diff (JSON-pretty when possible), auth, cookies, follow / insecure / compressed flags. |
| Single curl mode | If only one pane has a valid curl, a summary still shows parsed fields; add a second command to diff. |
| Raw diff | Line-based diff of the full command text—useful for odd flags or when structured parsing is incomplete. |
| Shared parser | Same parseCurl pipeline as curl → code for consistent behavior. |
| Samples & swap | Both samples loads example curls; Swap exchanges A/B; Clear A/B resets panes. |
| History | History panel for recent documents (IndexedDB-backed flow consistent with other Spoold tools). |
| Handoff | Compatible with Spoold Magic Box / #data= style landing so the left command can be pre-filled from detection (see in-app guide). |
- Open curl compare.
- Paste curl A (original) and curl B (modified) into the diff editor, or try Both samples.
- Read Structured comparison for method, URL, query, headers, body, auth, and cookies.
- Use the raw section when you need full-command differences or the parser skipped a niche flag.
- Optionally open History to reload recent work.
The UI may persist editor content using local stash keys such as spoold-curl-compare-a and spoold-curl-compare-b (session continuity in the browser). History uses Spoold’s document storage (e.g. IndexedDB) so you can return to recent comparisons—still on your device, not sent to Spoold as “curl comparison as a service.”
- Covers common curl flags used in typical API calls (
-X,-H,-d,-u,-b,-L,-k,--compressed, and more—see the in-page Guide for nuance). - Does not execute requests or validate against a live server—this is a text and structural diff only.
- If one or both commands fail to parse, you still get parse errors per side (when applicable) and the raw line diff of the full strings.
- curl → code — Convert a single curl to fetch, Axios, Python, etc.
- Text Diff — Generic two-text compare.
- URL inspect — Break down URLs and parameters.
- Built with Next.js (React) and Monaco Editor (
DiffEditor). - Uses
difffor line diffs and shared curl parsing utilities undersrc/lib/. - No server-side curl execution in this tool: your commands stay in the browser unless you choose a separate Spoold share/cloud flow that applies to other tools.
Spoold: github.com/thespoold/spoold — clone, pnpm install, pnpm dev, then open /tools/http/curl/compare.
Spoold — Paste. Detect. Do. · spoold.com