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I will customize, update, or refactor HTML CSS javascript PHP code for your website
Juan H
Top Rated
4.8
4.8
Gig Summary
About this gig
Need custom modifications, layout tweaks, or feature enhancements for your existing website?
Instead of relying on rigid page builders or bloated plugins, I edit and customize your HTML, CSS, JavaScript, TypeScript, and PHP code natively to match your exact design and technical requirements.
WHAT I CUSTOMIZE AND EDIT:
- Frontend Styling: CSS3/Sass layout adjustments, responsive design fixes, custom animations
- JavaScript Behavior: Modifying interactive widgets, DOM logic, sliders, modal popups, dynamic forms
- Backend Adjustments: Modifying PHP scripts, form submission handlers, custom data fields
- Component Extension: Adding custom sections, headers, footers, or sidebars to existing pages
WHY CHOOSE A TOP RATED DEVELOPER?
- Clean & Maintainable Code: Modifications are well-commented and won't break existing features
- 10+ Years Experience: Over 4,000 successful web development projects delivered
- Safe Workflow: Updates performed on local/staging environments whenever possible
Please contact me with your site URL and customization requirements BEFORE ordering!
Respect third-party rights
Please be aware that it is against Fiverr's policies for sellers to include themes, templates, or any other elements that infringe third-party rights or applicable laws in the delivered work. Read more about in our Guide to Responsible Digital Creation.
Get to know Juan H
Juan H
Full Stack Web, AI and Shopify Developer, Custom APIs and Browser Automations
Top Rated
- FromVenezuela
- Member sinceDec 2013
- Avg. response time1 hour
- Last delivery1 month
Languages
English, Spanish
Web & AI Developer with 10+ years of experience and 4,000+ completed projects. I specialize in scalable full-stack web applications, custom Chrome extensions (Manifest V3), e-commerce (Shopify), and AI agent & workflow integrations (OpenAI/Claude/Gemini).
My solutions have reduced delivery times by 40% and boosted user engagement by 25%.
Core Stack & Tools: Javascript/TypeScript, React, Next.js, Node.js, Astro, Tailwind CSS, PHP, MySQL, PostgreSQL, MongoDB, Firebase, Supabase, Shopify & Browser Automation.
Let's turn your requirements into a scalable, production-ready web or AI solution!
My Portfolio
Other Website Maintenance Services I Offer
FAQ
Can you customize existing code without breaking my site's functionality?
Yes! I write clean, modular modifications and test them thoroughly on staging or local setups to ensure zero downtime or conflicts with your existing code.
What details do you need to start modifying my site?
I need your site URL, a clear description or mockups of the desired customization, and FTP/cPanel or repository credentials to access the source files.
What if I need a completely new feature built from scratch instead of editing existing code?
If your project requires building a new custom module or integration from scratch, I will provide a custom scope and offer tailored to your exact needs.
Reviews
354 reviews for this Gig
| (350) | ||
| (1) | ||
| (0) | ||
| (2) | ||
| (1) |
Rating Breakdown
- Seller communication level
- Quality of delivery
- Value of delivery
Sort By
Most relevant
C 
covertcon
United States
He did exactly what I needed and very quickly. Thanks!
$200-$400
Price
2 days
Duration
Helpful?A androidthor
Spain
Todo muy bien, además muy rápido
$200-$400
Price
4 days
Duration
Helpful?P perongiig
Spain
Me cobró demasiado por cambiar cuatro líneas de código
$50-$100
Price
4 days
Duration
J 
Seller's Response
Helpful?C chelseagraving
Australia
Ongoing collaborationJuan was very very pleasant to work with. Was very understanding with changes we wanted to make and delivery time was exceptionally quick! Highly recommended
$50-$100
Price
2 days
Duration
Helpful?Z zachthrower
United States
Delivered as requested
$50
Price
1 day
Duration
Helpful?
Reviews
354 reviews for this Gig
| (350) | ||
| (1) | ||
| (0) | ||
| (2) | ||
| (1) |
Rating Breakdown
- Seller communication level
- Quality of delivery
- Value of delivery
Sort By
Most relevant
C covertcon
United States
He did exactly what I needed and very quickly. Thanks!
$200-$400
Price
2 days
Duration
Helpful?A androidthor
Spain
Todo muy bien, además muy rápido
$200-$400
Price
4 days
Duration
Helpful?P perongiig
Spain
Me cobró demasiado por cambiar cuatro líneas de código
$50-$100
Price
4 days
Duration
J Seller's Response
Helpful?C chelseagraving
Australia
Ongoing collaborationJuan was very very pleasant to work with. Was very understanding with changes we wanted to make and delivery time was exceptionally quick! Highly recommended
$50-$100
Price
2 days
Duration
Helpful?Z zachthrower
United States
Delivered as requested
$50
Price
1 day
Duration
Helpful?
