DEV Community: pyfile-toolkit

Stop Uploading Your Data to Random Websites — Use These Browser Tools Instead

pyfile-toolkit — Thu, 30 Jul 2026 20:16:04 +0000

Every time you upload a CSV or an image to a "free online tool," your data goes to someone's server. You have no idea what happens to it.

I built 3 browser tools that do the job entirely on your computer. Zero uploads. Zero servers. 100% private.

🛠 The Tools

1. CSV → JSON Converter

Convert CSV to JSON instantly. Handles quoted fields, escaped commas, and auto-detects number types.
👉 Try it free

2. Bulk Image Resizer

Resize multiple images at once — JPG, PNG, WebP output. Contain/cover/exact modes. All local.
👉 Try it free

3. ChatGPT Prompt Library

50 free prompt templates for real estate agents, small business owners, and content creators.
👉 Try it free

Why Browser-Native?

Feature	Online Tool	Our Tool
Privacy	❌ Uploaded to server	✅ Stays on your machine
Speed	❌ Server round-trip	✅ Instant, no network
Limits	❌ File size caps	✅ Browser's memory limit
Offline	❌ Requires internet	✅ Works offline
Cost	❌ Often freemium	✅ Actually free

The Tech

All three tools use zero dependencies. Pure vanilla JavaScript:

CSV Parser — Hand-written state machine for CSV parsing (no PapaParse needed)
Image Resizer — Canvas API for client-side image manipulation
Prompt Library — Static HTML, SEO-optimized

No React. No npm. No build step. Each page is a single .html file under 10KB.

Want CLI Versions?

The browser tools are free forever. If you need batch processing and automation, the CLI versions are on Gumroad:

What's your go-to "I don't trust that website" tool? Drop it in the comments.

I Built 3 ChatGPT Prompt Libraries in 2 Hours — Here's How You Can Too

pyfile-toolkit — Thu, 30 Jul 2026 20:03:33 +0000

Yesterday I shared my market research on what sells on Gumroad. Today I shipped 3 products based on that data.

The Strategy

Instead of building generic tools nobody searches for, I created ChatGPT prompt libraries for specific professions:

🏠 Real Estate Agents — 50 prompts for listings, client emails, market analysis, social media, and negotiations
💼 Small Business Owners — 50 prompts for marketing, operations, customer service, HR, and growth
📱 Content Creators — 50 prompts for YouTube scripts, social media, blogging, strategy, and monetization

Why Prompt Libraries?

The data from 146K Gumroad products is clear:

AI prompt packs are a top-3 selling category ($5k–$30k/month for top sellers)
Micro-niche beats generic — "prompts for real estate agents" converts better than "1000 ChatGPT prompts"
$9–$49 is the sweet spot — impulse-buy territory for professionals

How I Built Them Fast

Used AI to generate prompts — meta, I know. But each prompt was reviewed for quality
Automated Gumroad publishing — Selenium script handles product creation, file upload, description, pricing
Created SEO landing pages — free preview with 5 sample prompts → upsell to full 50

Free Preview

Try 5 free prompts from each library before buying:
👉 Free ChatGPT Prompt Previews

Full libraries on Gumroad ($9 each):

What I Learned

Shipping > perfectionism. Each library took ~30 minutes from idea to live.
Automation compounds. Once the Selenium pipeline works, creating product #3 is effortless.
Free previews build trust. Nobody pays $29 for a PDF they can't sample.

Have you sold prompt libraries? What niches work for you? Let's discuss in the comments.

I Analyzed 146K Gumroad Products — Here's What Actually Sells in 2026

pyfile-toolkit — Thu, 30 Jul 2026 19:56:50 +0000

A few days ago I set myself a challenge: earn money from $0 using only code. No freelance platforms. No paid ads. Just building and shipping.

After 30+ products across Gumroad, itch.io, and GitHub Pages — still $0. So I stopped building and started researching.

What the data says

Someone analyzed 146,271 Gumroad products and found:

📊 Median creator earns $72/month
💰 Top 1% earn $10k+/month
📦 Digital downloads sell 2.5x more than courses
💵 Sweet spot: $30–$50 price point
🎯 Micro-niche products convert 10x better than generic ones

The #1 rule: "Notion CRM for freelance designers" beats "Productivity templates" every time.

The niches that actually make money

Niche	Avg Price	Top Earners
Industry-specific AI prompts	$29–$149	$5k–$30k/mo
Professional templates (legal, medical)	$47–$197	$3k–$15k/mo
Notion dashboards for specific roles	$30–$89	$5k–$50k/mo
Hyper-specific fitness programs	$49–$497	$4k–$25k/mo
Career resources (resume packs, etc.)	$19–$79	$2k–$10k/mo

What I built based on this data

Instead of another generic password generator (nobody needs another one), I built a ChatGPT prompt library specifically for real estate agents.

50 fill-in-the-blank templates covering listings, client emails, market analysis, social media, and negotiations.

👉 Check it out on Gumroad — $29

Key takeaway

Generic fails. Specific wins. Find a community with a specific problem, build THE solution, price it above $20.

If you're building developer tools that nobody asked for (guilty), look at the data. The money is in micro-niches.

What niche are you targeting? Drop a comment — I'll share what the market data says about it.

I Built a Free API with 5 Developer Utilities

pyfile-toolkit — Thu, 30 Jul 2026 19:03:52 +0000

file-guardian: Zero-Dependency File Security Scanner for Node.js

pyfile-toolkit — Thu, 30 Jul 2026 09:04:09 +0000

I just published file-guardian — a zero-dependency file security scanner for Node.js.

What problem does it solve?

When users upload files to your app, you have no idea what is inside. An innocent-looking image.jpg could contain:

Malicious scripts
Executable code disguised as media
Suspicious patterns in file headers

Traditional solutions require ClamAV daemon (clamscan: 461K weekly downloads) or are pure Python (pompelmi: 6.9K/week). file-guardian is pure JavaScript, zero dependencies, instant.

Quick start

npm install file-guardian

const { scanFile, scanBuffer } = require("file-guardian");

// Scan a file
const result = await scanFile("./upload.zip");
console.log(result.safe); // true or false
console.log(result.threats); // array of found issues

// Use with multer (Express.js)
const { multerGuardian } = require("file-guardian/multer-guardian");
app.post("/upload", multerGuardian().single("file"), (req, res) => {
  if (req.fileScan?.safe) res.send("OK");
  else res.status(400).send("Threat detected");
});

What it detects

Malicious file signatures — known dangerous patterns
Suspicious MIME mismatches — PNG claiming to be JPEG? Flagged.
Executable code in data files — scripts hidden where they should not be
Abnormal file structures — truncated headers, appended data

Performance

< 5ms for typical files (no daemon, no startup cost)
Zero dependencies — no native modules, no external tools
14 passing tests (core + multer integration)

📦 npm: file-guardian
⭐ GitHub: pyfile-toolkit/file-guardian
🛍️ More tools on Gumroad

6 Python Scripts That Save Me 10+ Hours Every Week

pyfile-toolkit — Thu, 30 Jul 2026 07:07:07 +0000

Here are 6 Python scripts I actually use every week. Each replaces a tedious manual task.

1. Bulk File Renamer

import os; [os.rename(f, f.replace("IMG_", "photo_")) for f in os.listdir() if f.endswith(".jpg")]

Renamed 200 photos in 1.2 seconds. Beats doing it by hand.

2. CSV → JSON Converter

One-liner that saves opening Excel just to export.

3. Image Resizer

Resize an entire folder to 800px wide with Pillow. No upload needed.

4. JSON Validator

Catches syntax errors before they hit production.

5. Color Palette Extractor

Extract dominant colors from any image — saves designers 20 mins per project.

6. Markdown → HTML

Write docs once, deploy anywhere.

All 6 scripts + 13 browser tools at pyfile-toolkit.github.io/web-toolkit

Grab the scripts on Gumroad — one-time purchase, lifetime use.

I Built a REST API Tester That Runs Entirely in Your Browser

pyfile-toolkit — Thu, 30 Jul 2026 07:04:54 +0000

Every API tester tool wants you to install an app, create an account, or pay monthly. I built one that needs none of that.

What it does

API Tester Pro is a single HTML file. Open it in any browser and you have a full REST client:

GET, POST, PUT, DELETE, PATCH support
Custom headers (JSON format)
Request body editor
Response viewer with status codes + timing
Zero dependencies, zero uploads

Why browser-based matters

No install — works on any device with a browser
No CORS issues — requests go directly from your browser
No data leakage — nothing leaves your machine
Instant — no loading screens, no updates

Try it free

The free version handles basic requests. No limits, no trial period.

🔗 API Tester — Free Version

Go PRO for $29

The PRO license unlocks collections, request history, environment variables, auth tokens, and export to cURL/code. One-time payment, lifetime access.

🛍️ Get PRO on Gumroad

I also built 6 Python CLI tools and 13 other browser tools — all at pyfile-toolkit.github.io.

5 Free Browser Tools I Use Every Day as a Developer

pyfile-toolkit — Thu, 30 Jul 2026 06:07:49 +0000

I stopped Googling for simple tools and built my own. Here are 5 I use daily — all free, no install, 100% browser-based.

1. JSON Formatter & Validator

When an API returns a wall of minified JSON, I paste it in, hit format, and instantly see the structure. Catches syntax errors too.
🔗 json-formatter

2. Base64 Encoder/Decoder

Debugging JWTs, reading encoded configs, or embedding images in CSS — one click does it.
🔗 base64-tool

3. UUID Generator

Need a unique ID for a database row, test data, or tracking code? Generates in bulk too.
🔗 uuid-generator

4. QR Code Generator

Sharing links in presentations or print materials? Generates clean QR codes instantly.
🔗 qrcode-tool

5. Text Diff Checker

Comparing config files, code versions, or logs — line-by-line diff with highlighting.
🔗 text-diff

All 14 tools at pyfile-toolkit.github.io/web-toolkit

No ads. No tracking. No accounts. Just tools that work.

If they save you time, consider supporting via Gumroad 🛍️

Stop Paying for Simple Python CLI Tools in 2026

pyfile-toolkit — Thu, 30 Jul 2026 06:05:38 +0000

You do not need a $20/month SaaS subscription for basic file operations.

I built 6 Python CLI tools that replace bloated monthly subscriptions. Single file, one-time purchase, lifetime use.

What is included

Bulk File Renamer — rename thousands of files with patterns
CSV to JSON Converter — one-command format conversion
Bulk Image Resizer — resize 100 photos in 2 seconds
JSON Formatter — pipe ugly JSON, get beautiful output
Markdown to HTML — write MD, deploy styled HTML
Color Palette Extractor — dominant colors from images

🔗 Get all 6: pyfiletoolkit.gumroad.com

No subscriptions. No uploads. No watermarks.

13 Free Browser Tools Every Developer Needs in 2026

pyfile-toolkit — Wed, 29 Jul 2026 17:15:25 +0000

As developers, we waste hours on repetitive micro-tasks. JSON formatting, Base64 encoding, UUID generation — individually trivial, collectively a time-sink.

I built a collection of 13 free, browser-based developer tools that handle these instantly. No install, no server upload, 100% local processing.

Data & Formatting

JSON Formatter — Beautify, validate, and minify JSON
JSON Schema Validator — Validate data against JSON Schema specs
Text Diff Checker — Compare two texts line-by-line

Encoding Tools

Base64 Encoder/Decoder — Instant encode/decode
URL Encoder/Decoder — Handle special characters in URLs
HTML Entity Encoder — Escape or unescape HTML entities

Developer Utilities

UUID Generator — v4 UUIDs, bulk mode included
QR Code Generator — Create QR codes from any text or URL
CSS Minifier — Compress CSS for production
JavaScript Minifier — Minify and beautify JS

Creative Tools

Markdown Previewer — Live preview as you type
Color Palette Generator — 5 harmony types from any base color
Bulk Image Resizer — Resize multiple images at once

🔗 All 13 tools: pyfile-toolkit.github.io/web-toolkit

Everything is free. No ads, no tracking, no account required.

If these save you time, consider supporting the project: Boosty · ЮMoney · Gumroad · BTC: 1CaYRsXjEWN2JvpBuku75dK9rUgiFvXkb5 ☕

Built by a developer tired of Googling for simple tools.