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Feedback that cuts through

One script tag turns any HTML mockup into a feedback machine. Pinpoint elements, capture context, query with CLI.

Moritz Bierling Built by @bierlingm
Install 
curl -fsSL https://spikes.sh/install.sh | sh
See Features GitHub
your-mockup.html
🗡️
index.html 
<!-- Add before </body> -->
<script src="https://spikes.sh/widget.js"></script>
No accounts
No tracking
MIT licensed
8KB gzipped
Features

Precise feedback. Zero friction.

Everything you need to collect and act on mockup feedback. Nothing you don't.

+

Element-level precision

Click any element to spike it. Captures CSS selector, bounding box, and text content. No more "the thing on the left."

/

One script tag

Works on file://, localhost, any domain. No build step, no accounts, no tracking scripts.

$

CLI that speaks JSON

Every command outputs JSON. Pipe to jq, feed to AI agents, integrate with your workflow.

~

Local-first

Feedback lives in localStorage by default. Your data, your control. Deploy to your Cloudflare for team sync.

{}

Structured data

Every spike includes page, reviewer, rating, timestamp, viewport, and element data. Query anything.

8K

Tiny footprint

8KB gzipped. No dependencies. No external requests except to your own endpoint.

How it works

Add, share, query

1

Add the widget

One script tag in your HTML mockup. Or use spikes inject to add it to a whole directory.

2

Share with reviewers

They click the button, rate pages, spike elements. First-timers enter their name once.

3

Query feedback

Use the CLI to list, filter, export. Find hotspots. Feed to agents.

Use Cases

Built for

Solo designers. Client reviews. Team handoffs.

01

Design Reviews

Precise feedback on mockups before dev handoff

02

Client Feedback

Share prototypes, collect structured input

03

Prototype Testing

Capture reactions on specific elements

04

QA Handoff

Document issues with exact CSS selectors

CLI

A CLI that agents love

Every command supports --json for machine-readable output. Inject widgets, serve mockups, query feedback, find hotspots—all from the terminal.

List and filter feedback by page, reviewer, or rating
Find hotspots—elements with the most spikes
Export to JSON, CSV, or JSONL for processing
Sync with remote endpoints you control
Terminal 

                

            

        

    

    
    

        

            
Comparison

            
Why Spikes?

            

                How we stack up against other feedback tools.
            

            
            

                

                    
                        

                            Feature
                            Spikes
                            InVision
                            Hotjar
                            Pastel
                        

                    
                    
                        

                            No account required
                            ✓
                            ✗
                            ✗
                            ✗
                        

                        

                            Works offline / local files
                            ✓
                            ✗
                            ✗
                            ✗
                        

                        

                            CLI with JSON output
                            ✓
                            ✗
                            ✗
                            ✗
                        

                        

                            Self-hosted option
                            ✓
                            ✗
                            ✗
                            ✗
                        

                        

                            No tracking / privacy-first
                            ✓
                            ✗
                            ✗
                            ✗
                        

                        

                            Element-level targeting
                            ✓
                            ✓
                            ✗
                            ✓
                        

                        

                            100% free
                            ✓
                            ✗
                            ✗
                            ✗
                        

                        

                            Open source (MIT)
                            ✓
                            ✗
                            ✗
                            ✗
                        

                    
                

            

        

    

    
    

        

            
Pricing

            
Free. Really.

            

                100% of features, forever, no asterisks. MIT licensed.

                If Spikes earns its place in your workflow, spike us back.
            

            
            

                

                    
The Tool

                    
$0

                    
Everything. Forever.

                    
                    

                        
Full widget + CLI

                        
Unlimited mockups

                        
Unlimited reviewers

                        
JSON/CSV export

                        
Deploy to your infrastructure

                        
MIT licensed, no tracking

                    

                    
                    Get Started
                

                
                

                    
Spike Us Back

                    
Pay what you feel

                    
$9 / $19 / $29+

                    
                    

                        
Same features (you already have them)

                        
Badge for your site

                        
Name on supporters page

                        
Priority GitHub issues

                        
Agency? $149 for whole team + logo

                        
Our actual gratitude

                    

                    
                    Spike Us Back
                

            

            
            

                Like Sublime Text: use it free forever, pay when it earns its place.
            

        

    

    
    

        

            
Updates

            

                New features, no spam.
            

            
        

    

    
    

        

            
Try it now

            

                This page has Spikes installed. Click the 🗡️ in the corner.
            

            

                Rate this page, or click any element to spike it.
            

        

    

    
    

        

            
Get started

            
Install in seconds

            

                Choose your method. Be collecting feedback in under a minute.
            

            
            

                

                    

                        
Widget (add to HTML)

                        <script src="https://spikes.sh/widget.js"></script>
                    

                    
                

                

                    

                        
CLI (one-liner)

                        curl -fsSL https://spikes.sh/install.sh | sh
                    

                    
                

                

                    

                        
CLI (with Cargo)

                        cargo install spikes