Forem: Davron Yuldashev

I Built 6 Free Browser-Based Tools — 50+ Utilities, No Signup, No Tracking

Davron Yuldashev — Tue, 07 Apr 2026 05:00:06 +0000

All tools are free. Processing happens in your browser or on a private server. No accounts, no ads, no tracking.

Over the past 6 weeks I built a portfolio of free online utility tools at davrapps.dev. Here's what shipped and how it's built.

The Apps

🛠️ DevTools — 28 Developer Utilities

Every tool runs 100% client-side — nothing is sent to any server. Check the Network tab if you don't believe me.

Text & Data

JSON Formatter & Validator
YAML ↔ JSON Converter
TOML ↔ JSON Converter
Diff Checker — compare two texts side-by-side
Text Statistics — word count, reading time, character frequency
String Case Converter — camelCase, snake_case, SCREAMING_SNAKE, kebab-case
Lorem Ipsum Generator

Encoding & Crypto

Base64 Encode/Decode
URL Encoder/Decoder
HTML Entity Encoder/Decoder
Hash Generator — MD5, SHA-1, SHA-256, SHA-512 (Web Crypto API)
JWT Decoder — inspect header + payload without a secret
Password Generator — cryptographically secure
Image to Base64

Dev Helpers

Regex Tester — real-time matching with group highlighting
UUID Generator — bulk v4 UUIDs
Unix Timestamp Converter — epoch ↔ human-readable with timezone
Number Base Converter — binary, octal, decimal, hex
Cron Expression Parser — plain English explanations
SQL Formatter
CSS Minifier
Markdown Preview
Color Converter — HEX ↔ RGB ↔ HSL
CSS Gradient Generator — linear/radial/conic, CSS + Tailwind output
Tailwind CSS Color Explorer

👉 devtools.davrapps.dev

🖼️ ImgTools — 7 Image Utilities

Server-side processing with Sharp/libvips on a private VPS — files are never stored.

Compress — MozJPEG, up to 80% size reduction
Resize — custom dimensions + social media presets
Crop & Rotate
Format Convert — JPEG, PNG, WebP, AVIF, GIF, TIFF
Watermark — text or image
Background Removal

👉 imgtools.davrapps.dev

📄 PDFKit — 9 PDF Tools

No file size limits. No watermarks on output. No account needed.

Merge, Split, Compress, Rotate, PDF ↔ Image, Password Protect, Watermark, Add Page Numbers.

👉 pdfkit.davrapps.dev

🔲 QRKit — 8 QR Code Tools

Generate (with logo + custom colors), Scan (file or camera), WiFi QR, vCard QR, Batch Generator, Decode, Color Picker.

👉 qrkit.davrapps.dev

📸 Picefy — Screenshot Beautifier

Turn plain screenshots into polished visuals: gradient backgrounds, rounded corners, drop shadow, device frames. Export as PNG.

👉 picefy.davrapps.dev

📦 ShipKit — Next.js + Bun SaaS Boilerplate ($49)

Full-stack starter: Next.js 16, Bun, Elysia.js, Better Auth, Polar.sh payments, PostgreSQL + Drizzle ORM, shadcn/ui, i18n, dark mode.

👉 shipkit.davrapps.dev

Monetization

App	Free limit	Pro
DevTools	Unlimited	—
ImgTools	5 ops/day	$3/mo
PDFKit	5 ops/day	$5/mo
QRKit	5 ops/day	Coming soon
Picefy	5 exports/day	$5/mo
ShipKit	—	$49 one-time

Payments via Polar.sh (Stripe under the hood, but with a much better OSS-friendly DX).

Tech Stack

All apps share the same foundation:

Next.js 16 (App Router, SSG for all tool pages)
Bun runtime + package manager
Elysia.js API layer (Bun-native, ~3x faster than Express in benchmarks)
Better Auth — email/password + OAuth, sessions in PostgreSQL
shadcn/ui + Tailwind CSS — every app has dark/light mode
PostgreSQL + Drizzle ORM
i18n via next-intl (EN/RU/UZ)

Deployed on a Hetzner CAX21 ARM (~$8/mo total for all 6 apps). Each app is a systemd service behind nginx, its own port pair.

Key Decisions

Client-side by default. For anything that doesn't need a server (formatters, converters, hash generators), everything stays in the browser. Zero upload risk, zero server cost.

SEO-first architecture. Each tool has its own URL, unique meta tags, FAQ with JSON-LD structured data. devtools.davrapps.dev/en/json-formatter and devtools.davrapps.dev/en/uuid-generator each target different search queries rather than competing as a single page.

One server, many apps. Rather than pay per-app VPS costs, everything runs on one ARM machine. Total infra cost for 6 apps + 14 services: ~$8/mo.

Current Status

6 apps live, 50+ total tools
MRR: $5 (early days)
Backlinks: 2 merged awesome-list PRs, 7 more open
Starting to appear in Brave/Bing — Google indexation in progress

What tools do you wish existed? Drop a comment — I might build it next.

I built a process manager with built-in crash detection and AI auto-fix (PM2 alternative)

Davron Yuldashev — Sat, 14 Mar 2026 10:42:06 +0000

You deploy a service, it crashes at 3 AM. You get a Sentry alert, SSH in, dig through logs, try to figure out what happened. Or you pay $26/month for Sentry plus integrate the SDK into every project.

I wanted crash detection and recovery built directly into the process manager — no extra services, no SDK, no dashboards. So I built Velos.

When a process crashes or throws an unhandled error, Velos detects it, runs AI analysis on the logs and stack trace, and sends a Telegram message with two buttons: Fix and Ignore. Tap Fix — an agent reads the logs, inspects the code, diffs recent changes, proposes a fix, and reports back. All without waking up your laptop.

How the crash flow works

Process crashes (or stderr matches panic/traceback/FATAL pattern)
  → Velos daemon detects it
  → AI analysis runs (Anthropic or any OpenAI-compatible API)
  → Telegram notification with [Fix] [Ignore] buttons
  → You tap Fix
  → Agentic loop starts: reads files, inspects git diff, runs commands
  → Result sent back to Telegram

Nothing happens without your approval. The agent has tools to read/edit files, run commands, and inspect git history — but it only acts when you tap Fix.

This also works for runtime errors before a crash. Velos watches stderr for panic/traceback/FATAL/ERROR patterns and fires an alert without waiting for the process to die. Closer to what Sentry does — but zero SDK, zero extra service.

Why Zig for the daemon?

Process management is fundamentally a systems problem: fork/exec, Unix sockets, signal handling, CPU/RAM monitoring via syscalls. Zig gives full control with zero runtime overhead — no hidden allocations, no GC, comptime metaprogramming for tight control over the binary.

The result: ~3 MB RAM idle, ~65 KB per managed process. PM2 sits at ~60 MB baseline because of V8.

Architecture:

Zig daemon (fork/exec, IPC, monitoring)
    ↓  C ABI FFI
Rust shell (CLI, REST API, MCP server, log engine, AI)

Zig core compiles to a static library (libvelos_core.a), linked into the Rust binary via C ABI FFI. Single binary, zero runtime dependencies.

IPC uses a binary protocol — 7-byte header (magic 0xVE10) + MessagePack payload over a Unix socket.

Smart Log Engine

Pattern clustering, error rate tracking, anomaly detection — runs fully local, zero LLM cost.

velos logs myapp --summary
# → "47 errors in last 10m, 3 patterns detected:
#    [1] DB connection timeout (×31)
#    [2] Rate limit exceeded (×12)
#    [3] File not found (×4)"

Instead of scrolling through thousands of raw log lines, you get a digest.

MCP server (for local AI workflows)

Velos also ships with a native MCP server — 13 tools for Claude Desktop or Claude Code to manage your local processes directly:

{
  "mcpServers": {
    "velos": {
      "command": "velos",
      "args": ["mcp", "start"]
    }
  }
}

Tools include: start_process, stop_process, restart_process, get_logs, health_check, get_metrics, search_logs, analyze_crash, and more. Useful for local dev environments where your AI agent is already running on the same machine.

Install

curl -fsSL https://releases.velospm.dev/install.sh | bash

Or Homebrew:

brew install Dave93/tap/velos

Current state

Velos is at v0.1.14, production-ready on macOS and Linux. Windows support is on the roadmap.

What's coming next:

XDG Base Directory compliance (tracking: #10)
Plugin system
Web dashboard
Benchmark suite vs PM2/supervisord/systemd

GitHub: Dave93/velos
Docs: velospm.dev

Happy to answer questions about the crash detection system, the Zig/Rust architecture, or the design decisions. What would you have done differently?