Browser Extensions
Free, private extensions for Chrome, Edge and Firefox. 100% local processing in your browser, zero telemetry, no sign-up required.
Dev Converters
Developer converters, fully offline in your browser.
Growth Checklist
Your dev growth, one step at a time.
SEO Snapshot
On-page SEO of the current page, in one click.
CSS Unit Companion
Convert px, rem, em, vh, vw and pt in a flash
Seniority Lens
Is this article for me? Estimate its target seniority in one click.
Tool Finder
Describe the task, the on-prem AI finds the right tool.
Color Studio
Pick any color from the page and convert it to HEX, RGB, HSL and OKLCh
StatePeek
Simulate rendering states on the active tab: dark, reduced motion, high contrast.
CWV Live
Your tab's real Core Web Vitals, live
Chat Shield
Mask sensitive data before you talk to the AI
CSS Inspector
Box-model and font of the element under your cursor, no DevTools
Contrast Vision
Real-text WCAG and APCA contrast + colorblindness simulation on the page.
Viewport Tester
Test responsive breakpoints in a real window
Cookie Inspector
Cookies, localStorage and sessionStorage of the active domain, with security flags at a glance.
JWT Session
Find and decode your session JWTs, with expiry countdown and alg:none alerts
Headers Panel
Real navigation response headers, CSP and security score.
Text Diff
Compare two texts line by line, right in your browser
Mock Filler
Fill forms with realistic Italian fake data from the right-click menu
Robots & Indexability
One verdict: indexable or blocked?
Schema Peek
Inspect the page's JSON-LD and catch mismatches with the real content
Image Audit
Make your images accessible and fast, in one click
Level Check
Which step are you at? Self-assess on 4 axes and find your gaps.
DevFlash
Dev flashcards with spaced repetition, on every new tab
Prompt Vault
Your reusable prompt library, with variables
Token Pulse
Live tokens, cost and context budget for your AI assistants
CodeLens on-prem
Explain and review selected code with zero data leaks
Regex Genie
Describe it in plain language, get the regex explained and tested
Page Summarizer
On-prem page summary with weighted keywords
A11y X-Ray
Accessibility X-ray: landmarks, headings, missing alt/labels and tab order, in one click.
Screenshot Annotate
Capture, annotate and share bug reports without ever leaving your browser
CORS Diagnoser
Find out why a cross-origin request gets blocked
API Workbench
Lightweight REST client that even reaches localhost
Webhook Studio
Build, HMAC-sign and send webhooks — even to localhost, no relay
UA Switcher
Spoof User-Agent and Client Hints on a single tab
JSON Lens
Turn raw JSON responses into a navigable tree with search and JSONPath
Gradient & Shadow
CSS gradients and shadows with live preview, fully offline.
Hreflang Lens
Validate hreflang: self-reference, x-default, codes and reciprocity
Link Sweep
Check every link on the page, with no false alarms.
RAL Snapshot
From gross salary to net take-home in one click, with typical dev-level ranges
TermTip
Instant dev definitions from a local dictionary
JobSkill Radar
Required skills and seniority level from any job posting
Chat Index
Folders and full-text search for your AI chats
Continue Please
Detect truncated AI replies and stitch them back without duplicates
Pin Point
Message bookmarks and cross-assistant minimap
Multi-Ask
One prompt, every assistant: prefill and compare.
Draft Guard
Never lose a draft you wrote to an AI assistant again.
Shortcut Smith
Identical hotkeys across every AI assistant
Ask Federico
Ask federicocalo.dev's content, answers from the on-prem AI.
CF Explainer on-prem
Select an Italian tax code, get birth details and sex — validated locally, enriched on-prem.
YAML ⇄ JSON
Convert YAML and JSON both ways, with the exact error line
Dev Exporter
Export your AI chats to Markdown, JSON or a ZIP with code-blocks as files.
Codeblock Pro
Copy, download and ZIP AI assistant code blocks