DEV Community: Ceco Gatev

5 more no-signup dev tools I built (regex, JWT, hashes, CSV↔JSON, calc) — all run offline

Ceco Gatev — Sun, 31 May 2026 03:35:17 +0000

A while back I shared some tiny browser-only tools I'd built to dodge ad-walls and "paste your data into our server" pages. I kept going — here are five more, all client-side, no signup, nothing uploaded.

Regex Tester

Live match highlighting, capture groups, a match count, and the g/i/m/s flags as toggles. Invalid patterns show the error instead of silently failing.
👉 https://tsetsobg.github.io/tools/regex-tester/

JWT Decoder

Paste a token, see the decoded header and payload with the expiry shown in a human-readable date (and flagged if expired). It decodes only — it doesn't pretend to verify the signature, and the token never leaves your tab.
👉 https://tsetsobg.github.io/tools/jwt-decoder/

SHA Hash Generator

SHA-256 / SHA-1 / SHA-512 of any text, live, via the Web Crypto API.
👉 https://tsetsobg.github.io/tools/hash-generator/

CSV ↔ JSON Converter

Both directions, with a proper CSV parser that handles quoted fields containing commas, escaped quotes and newlines (the usual thing that breaks naive split-on-comma converters).
👉 https://tsetsobg.github.io/tools/csv-to-json-converter/

Scientific Calculator

Order of operations, parentheses, powers/roots, trig, logs, π/e, degrees/radians — built on a small shunting-yard parser rather than eval, so it's safe to paste anything in.
👉 https://tsetsobg.github.io/tools/scientific-calculator/

Why offline / no-signup?

Each is a single static page with a small inline script — no backend, no account, no tracking in the hot path. Fast, works on a plane, and your input stays in the tab. The full set lives here: https://tsetsobg.github.io/tools/

What small dev utility do you keep re-googling? I'm still adding to the set and genuinely take requests.

8 tiny browser tools I built that run 100% offline (no signup, no tracking)

Ceco Gatev — Sun, 31 May 2026 01:38:53 +0000

I kept hitting the same annoyance: I'd search for something simple like a JSON formatter or a Base64 decoder, land on a page covered in ads and popups, and half of them want you to paste your data into their server. For anything sensitive that's a hard no.

So I started building my own as plain static pages. They run entirely in your browser — nothing is uploaded, nothing is logged, and they work offline once the page has loaded. No signup, no account, no cookie wall. Here are eight I reach for most.

1. JSON Formatter & Validator

Paste messy JSON, get it pretty-printed (or minified), with the parse error shown if it's invalid. All client-side.
👉 https://tsetsobg.github.io/tools/json-formatter/

2. Base64 Encode / Decode

Encode or decode Base64 text both ways as you type. Handy for quick data-URI and token poking.
👉 https://tsetsobg.github.io/tools/base64-encode-decode/

3. UUID Generator

Generate v4 UUIDs one at a time or in bulk, copy with a click.
👉 https://tsetsobg.github.io/tools/uuid-generator/

4. Timestamp Converter

Unix epoch ↔ human-readable date, both directions, with your local and UTC time.
👉 https://tsetsobg.github.io/tools/timestamp-converter/

5. URL Encoder / Decoder

Percent-encode or decode query strings and components without firing up a console.
👉 https://tsetsobg.github.io/tools/url-encoder-decoder/

6. Hex ↔ RGB Converter

Convert colours between hex and RGB(A) — useful when a design tool gives you one and your CSS wants the other.
👉 https://tsetsobg.github.io/tools/hex-to-rgb-converter/

7. Markdown Table Generator

Paste CSV or tab-separated rows (straight from a spreadsheet) and get a clean, aligned Markdown table for your README.
👉 https://tsetsobg.github.io/tools/markdown-table-generator/

8. Unit Converter

Length, weight, temperature and volume in one place — type any field and the rest update.
👉 https://tsetsobg.github.io/tools/unit-converter/

Why static?

Each tool is a single static page with a small inline script — no framework, no backend, no analytics calls in the hot path. That means: it's fast, it works on a plane, and your input never leaves the tab. If you're privacy-conscious (or just tired of ad walls), that combination is surprisingly hard to find.

There are more in the same place if these are useful: https://tsetsobg.github.io/tools/

What tiny utility do you wish existed as a no-signup, offline page? I'm adding to the set and genuinely taking requests.

Stop hand-aligning Markdown tables

Ceco Gatev — Sun, 31 May 2026 00:41:35 +0000

Markdown tables are great until you're lining up pipes by hand in a README. Two things that save me every time:

1. The alignment row controls columns, not your spaces

You do not need the cells visually aligned in the raw text — renderers don't care. This renders fine:

| Name | Role | Status |
| :--- | :--- | :--- |
| Ada | Founder | Active |

The second row sets alignment:

:--- left, :---: center, ---: right.

So stop padding with spaces — it changes nothing in the output.

2. Generate from data instead of typing

Most table data already lives in a spreadsheet or CSV. Pasting from Excel/Sheets gives you tab-separated text; a tiny script turns it into a table:

const toMd = (tsv) => {
  const rows = tsv.trim().split('\n').map(r => r.split('\t'));
  const head = `| ${rows[0].join(' | ')} |`;
  const sep  = `| ${rows[0].map(() => ':---').join(' | ')} |`;
  const body = rows.slice(1).map(r => `| ${r.join(' | ')} |`).join('\n');
  return [head, sep, body].join('\n');
};

(Remember to escape literal | inside cells as \|.)

If you just want to paste-and-copy without the script, I put up a free one that auto-detects comma vs tab and lets you pick alignment: https://tsetsobg.github.io/tools/markdown-table-generator — runs in the browser, nothing uploaded. Same place has a JSON formatter for the other half of README pain.

What's your most-hated Markdown chore — tables, or escaping code blocks inside code blocks?

Browser one-liners that replace a bunch of online dev tools

Ceco Gatev — Sat, 30 May 2026 23:39:33 +0000

Half the "online tools" I used to Google are one line of built-in browser JS. Keeping these in your head (or a snippet file) saves a tab and keeps your data off random servers.

Random UUID (v4)

crypto.randomUUID(); // "9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d"

Cryptographically random, built in. For bulk, just loop it.

HEX → RGB

const [r,g,b] = hex.match(/\w\w/g).map(h => parseInt(h,16));

URL encode / decode (the right one)

encodeURIComponent(value); // a single query value
encodeURI(fullUrl);        // a whole URL, keeps / : ? & =
decodeURIComponent(s.replace(/\+/g,' '));

Base64 (UTF-8 safe)

btoa(unescape(encodeURIComponent(str)));   // encode
decodeURIComponent(escape(atob(b64)));     // decode

The naive btoa(str) throws on emoji/accents — the wrap fixes it.

JSON validate + format

JSON.stringify(JSON.parse(input), null, 2);

JSON.parse is your validator (it throws with the position).

I got tired of pasting into sketchy sites, so I made no-signup, runs-in-your-browser versions of these — handy when you want a UI but don't want to ship your data anywhere:

UUID generator: https://tsetsobg.github.io/tools/uuid-generator
Hex → RGB → HSL: https://tsetsobg.github.io/tools/hex-to-rgb-converter
URL encoder/decoder: https://tsetsobg.github.io/tools/url-encoder-decoder
JSON formatter: https://tsetsobg.github.io/tools/json-formatter

What's the one "online tool" you reach for that's secretly a browser one-liner?

Stop pasting data into online tools you don't control

Ceco Gatev — Sat, 30 May 2026 23:19:11 +0000

Quick PSA for anyone who reaches for an online JSON formatter, Base64 decoder, or "format my data" site: a lot of those tools send whatever you paste to their server. For random test data, fine. For anything with customer info, tokens, internal payloads, or config secrets — that's a quiet data-exfiltration risk you opted into without noticing.

The thing is, most of these operations don't need a server at all. They're built into the browser:

JSON: validate + format

JSON.stringify(JSON.parse(input), null, 2); // pretty
JSON.stringify(JSON.parse(input));          // minify

JSON.parse also throws a precise error on malformed input, which is your validator for free.

Base64: encode/decode (UTF-8 safe)

btoa(unescape(encodeURIComponent(str)));    // encode, emoji-safe
decodeURIComponent(escape(atob(b64)));      // decode

(The naive btoa(str) breaks on non-ASCII — the encodeURIComponent wrap fixes it.)

Color contrast: it's just math

WCAG contrast is relative luminance, not an RGB diff — linearize each channel, weight 0.2126/0.7152/0.0722, then (L1+0.05)/(L2+0.05). No API needed.

The point

If a tool can run in the browser, it should — your data never leaves the tab. I got tired of trusting random sites, so I built no-upload versions that do everything client-side:

JSON formatter/validator: https://tsetsobg.github.io/tools/json-formatter
Base64 encode/decode: https://tsetsobg.github.io/tools/base64-encode-decode
WCAG contrast checker: https://tsetsobg.github.io/tools/color-contrast-checker

All free, no signup, nothing sent anywhere. Next time you're about to paste something sensitive into a tool, check whether it actually needs a server first — usually it doesn't.

Do you audit the browser tools you paste data into, or just trust the popular ones?

WCAG color contrast, the quick version (with the actual numbers)

Ceco Gatev — Sat, 30 May 2026 22:39:04 +0000

Color contrast is one of the easiest accessibility wins to get right and one of the most common things audits flag. Here's the short, practical version I keep coming back to.

The numbers you actually need

Contrast is expressed as a ratio between text color and background, from 1:1 (identical) to 21:1 (black on white). The WCAG thresholds:

AA — normal text: at least 4.5:1
AA — large text (≈24px, or 19px bold): at least 3:1
AAA — normal text: at least 7:1
AAA — large text: at least 4.5:1

AA is what most teams target and what automated tools (Lighthouse, axe) check by default.

How the ratio is computed

It's based on relative luminance, not a naive RGB difference. For each channel you normalize to 0–1, linearize:

c_lin = c <= 0.03928 ? c/12.92 : ((c + 0.055)/1.055) ** 2.4

then L = 0.2126*R + 0.7152*G + 0.0722*B. The ratio is (Llight + 0.05) / (Ldark + 0.05). That 0.05 is the flare term so pure black on pure white tops out at 21, not infinity.

Practical tips

Don't trust your eyes — a gray that "looks fine" on your calibrated monitor often fails. Check the number.
Large text gets a lower bar (3:1), so headings can use lighter colors than body copy.
Placeholder text and disabled states are the usual offenders — they're often way under 4.5:1.
Brand colors rarely pass on white. Darken the text shade for body copy and keep the bright brand color for large headings or non-text accents.

Quick check

I put up a tiny client-side checker that shows the ratio and AA/AAA pass/fail for normal and large text, with a live preview: https://tsetsobg.github.io/tools/color-contrast-checker — paste two hex values and you'll see instantly whether a pairing works.

What contrast threshold does your team enforce in CI — AA, or do you push for AAA on body text?

The free, no-backend checklist for launching a static site

Ceco Gatev — Sat, 30 May 2026 22:11:32 +0000

When I ship a small static site (Astro, plain HTML, 11ty, whatever), the build is the easy part. The stuff that makes it look finished and keeps it compliant is what I always forget. Here's the checklist I now run through — all of it free, all client-side or static, no backend required.

1. A favicon (don't skip this)

A site with no favicon looks unfinished in the tab and in bookmarks. You need a few sizes:

<link rel="icon" type="image/png" sizes="32x32" href="/favicon-32.png">
<link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png">
<link rel="icon" type="image/png" sizes="512x512" href="/icon-512.png">

You can generate all three from an image or just a letter in the browser with a free favicon generator — it spits out the PNGs and the exact tags above.

2. Compress your images BEFORE you commit them

Unoptimized images are the #1 cause of slow static sites. A 3 MB hero PNG has no business being 3 MB. Resize to the max width you actually render and re-encode to JPG/WebP at ~80% quality — usually a 70–90% size cut with no visible difference. I do it client-side (canvas + toBlob) so nothing gets uploaded: image compressor.

3. The legal pages (the part everyone forgets)

The moment you add analytics, a newsletter form, or sell anything, you need:

a privacy policy (GDPR/CCPA + your analytics/email tools all require it),
terms & conditions,
a refund policy if you sell,
and a cookie consent notice if you set cookies.

You can draft all of them from templates in a few minutes (then adapt to your real practices): free legal-pages generators. Publish each at /privacy, /terms, /refunds and link them in your footer.

Not legal advice — templates are a starting point, not a substitute for a lawyer on high-stakes stuff.

4. Technical SEO basics

sitemap.xml + robots.txt (Astro's sitemap integration is one line).
Unique <title> + meta description per page.
Open Graph tags so links unfurl nicely.
Submit the sitemap in Google Search Console, and ping IndexNow on deploy so new pages get crawled fast.

5. A QR code for the printed/offline world

If the site backs a product, menu, or business card, generate a QR code that encodes the URL directly (not via a redirect that can expire), and export SVG for print.

That's the whole list. None of it needs a server or a paid plan — it's all static files and browser-side tools. What's on your pre-launch checklist that I missed?

(I build these free tools at CreatorLaunch — no signup, nothing uploaded.)

How to Make Money with AI in 2026 (Realistic Ways for Beginners)

Ceco Gatev — Sat, 30 May 2026 18:03:01 +0000

"Make money with AI" is everywhere in 2026 — and most of it is hype. Here's the honest version: AI doesn't make money; it makes you faster. The people actually earning use AI as leverage to deliver real services, build real products, and create genuinely useful content more efficiently than before. If you treat AI as a tool on top of a normal, honest business, the opportunities are real and beginner-friendly. Here are the realistic ways — roughly easiest-first.

1. Offer an AI-assisted service (fastest first dollar)

You get paid for an outcome, so you don't need an audience — just one client. Use AI to work faster and charge for the result:

Writing & editing — blog posts, product descriptions, emails, proofreading.
Simple design — social graphics, presentations, basic image edits.
Admin & data — cleaning spreadsheets, summarising documents, research.
Chatbot / automation setup — configuring simple assistants for small businesses.

Start on a marketplace where buyers already are (see how to get your first client on Fiverr and how to start freelancing with no experience). Price on the value delivered, not the minutes it took — see how to price freelance services.

2. Create and sell digital products

Use AI to speed up making products people pay for — then sell them repeatedly:

Templates, planners, prompts packs, mini-guides, worksheets.
AI helps you draft, outline, and iterate faster; you add the judgment, polish and real usefulness.

Sell on Gumroad, Etsy, or your own site (see how to sell digital products online, digital product ideas that sell, and best Etsy alternatives). A genuinely useful AI-prompt or template pack is a realistic first product.

3. Content + affiliate / ads (compounding)

Use AI to research and draft faster, then publish genuinely helpful content that earns through affiliate links and (later) ads. The catch: quality is the moat. Mass AI spam gets penalised; useful, accurate, well-edited content ranks and converts. (See how to use AI to write content — with the honesty and editing caveats — and how to start a blog that makes money.) Recurring SaaS affiliates pay best over time.

4. Productize a workflow

Once you've done a service a few times, turn the repeatable parts into a productized offer or a small tool/template others buy — higher margin, less per-order work. (See how to make money with digital products and the best AI tools for solopreneurs.)

How to start this week (no budget)

Pick one method above — for most beginners, a service is fastest.
Use free AI tiers — don't pay for tools until income justifies it.
Do one real thing — land one client, or ship one small product.
Be honest about AI use where platforms or buyers expect it, and always add your own judgment and editing — that's what makes the output worth paying for.
Reinvest and repeat. (See how to make your first $100 online.)

Want the whole funnel — landing page, email, checkout — free in one place as you grow? Try Systeme.io.

The honest bottom line

AI in 2026 is a genuine advantage, but it rewards the same things every business does: solving a real problem, doing quality work, and being consistent. Use it to deliver more value faster — as a service, a product, or content — and the money follows. Skip the "AI gets rich while you sleep" pitches; build something genuinely useful with AI's help, and you've got a real, low-cost path to income.

Keep reading

Originally published at tsetsobg.github.io. Some links are affiliate or product links — they never cost you extra.

How to Use AI to Write Content (Without Sounding Like a Robot)

Ceco Gatev — Sat, 30 May 2026 17:59:02 +0000

AI can genuinely cut your content time in half. It can also flood your audience with bland, soulless filler that quietly erodes trust — the kind of writing readers can now smell from a mile away. The difference isn't the tool; it's the workflow. Used as a drafting partner with you firmly in the editor's seat, AI is a real advantage for a solopreneur. Used as a "generate and publish" button, it's a slow-motion brand killer.

This guide is the workflow I actually use: what to hand to AI, what to never hand over, and how to get output that sounds like you instead of everyone else.

The mindset: AI drafts, you decide

The single rule that separates useful AI content from spam: the AI produces raw material; you supply the judgment. It can outline, draft, rephrase, and summarize. It cannot decide what's true, what matters to your specific audience, or what your honest opinion is. Those are yours, and they're exactly what make content worth reading.

If you remember nothing else: never publish a first draft, and never publish a claim you haven't verified.

What to delegate to AI (and what to keep)

Good jobs for AI:

Outlines and structure — "What questions should a post on X answer?"
First drafts of sections you'll heavily edit.
Repurposing — turning one article into posts, an email, a thread.
Rephrasing and tightening — "make this 30% shorter," "simplify this."
Overcoming the blank page — getting something down to react to.
Proofreading — grammar and clarity passes.

Keep these human:

Your opinions, stories, and hot takes — the reason anyone follows you.
Facts, numbers, names, and claims — AI invents these confidently. Always verify.
The final voice pass — read it aloud; cut anything you'd never actually say.

A 5-step workflow that keeps your voice

Brief it like a freelancer. Give the AI your audience, goal, voice, and key points before you ask for anything. Vague input is the #1 cause of generic output.
Make it interview you. Ask: "Before writing, ask me 5 questions to make this specific and original." Answering them injects the detail only you have.
Draft in sections, not all at once. Generate one section, fix it, then move on. Whole-article dumps are harder to salvage.
Edit ruthlessly for voice. Cut clichés ("in today's fast-paced world"), add a real example or opinion, and break up the even, robotic rhythm. This is where "AI content" becomes "your content."
Fact-check, then publish. Verify every statistic, quote, and claim. Your credibility is the asset.

Prompts that actually produce usable output

"You're an editor for [audience]. Before drafting, ask me 5 questions to make this post specific and original."
"Draft the section '[heading]'. Voice: [conversational/expert]. Short paragraphs, concrete examples, no clichés, no filler intro."
"Rewrite this so it sounds like a human wrote it — vary sentence length, cut hype, keep my meaning: [paste]."
"What's missing or weak in this draft? Be blunt: [paste]."
"Turn this article into 3 LinkedIn posts and one newsletter, each native to its format: [paste]."

If you'd rather not reinvent these each time, I packaged 50 tested prompts for exactly this kind of work — content, email, sales, and ops — into the Solopreneur's AI Prompt Pack. Fill in the brackets and go.

Where AI helps most across your business

Content is just one place AI earns its keep for a one-person business. It's also strong for drafting welcome email sequences, brainstorming content ideas when you're stuck, and outlining lead magnets and products. Pair that speed with an all-in-one platform like Systeme.io to actually publish, capture emails, and sell, and a solo operator can run what used to take a small team.

The honest bottom line

AI won't build your audience's trust for you — you do that, with real opinions, accurate information, and a voice that sounds human. What AI does is remove the friction between having something to say and saying it well. Keep your hand on the wheel, verify before you publish, and treat every draft as raw material. Do that, and you'll ship more and better content — without sounding like a robot.

Keep reading

Originally published at tsetsobg.github.io. Some links are affiliate or product links — they never cost you extra.

The Best AI Tools for Solopreneurs in 2026 (and How to Actually Use Them)

Ceco Gatev — Sat, 30 May 2026 17:57:52 +0000

"Best AI tools" lists are usually 50 links and zero judgment. This isn't that. As a solopreneur, you don't need every tool — you need a small stack that removes real friction without eating your budget or your voice. Below are the categories that genuinely move the needle for a one-person business, an honest take on each, and how to actually use them well.

A principle first: AI is leverage on judgment you already have, not a replacement for it. The solopreneurs who win with AI use it to go faster on the boring 80% so they can spend their judgment on the 20% that matters. The ones who lose hand over the judgment and ship generic slop.

1. A capable AI writing assistant (the core of the stack)

A strong general assistant (Claude, ChatGPT, Gemini — most have free tiers) is the single highest-leverage tool. Use it for outlines, first drafts, repurposing, brainstorming, summarizing research, and rephrasing — not for final, unedited, fact-unchecked publishing.

How to use it well: brief it like a freelancer (audience, voice, goal), make it interview you for specifics, and edit ruthlessly for voice and accuracy. Full workflow: how to use AI to write content without sounding like a robot. If you want a head start, a tested prompt pack saves you reinventing prompts each time.

2. Design & visuals

You no longer need a designer for everyday assets. Free/freemium tools (Canva and similar, plus AI image generators) cover social graphics, simple covers, thumbnails, and lead-magnet layouts. Use templates, keep it clean and readable, and stay consistent with one or two brand colors. Done-and-consistent beats fancy-and-sporadic.

3. All-in-one business platform

The biggest time sink for solopreneurs is stitching tools together. An all-in-one that handles your landing pages, email, automation, and product checkout in one place removes that friction. Systeme.io is a common pick because its free tier covers funnels, email, and file hosting — letting you run what used to need three separate subscriptions. Many also build their first store on Gumroad for standalone products.

4. Admin, scheduling & "second brain"

The unglamorous category that quietly saves hours:

A notes/second-brain tool (Notion, Obsidian, or even a single doc) to capture ideas so you never start from a blank page.
A social scheduler so a batch of content posts itself all week.
AI for inbox/admin — drafting replies, summarizing long threads, turning messy notes into SOPs.

5. Analytics (so you're not guessing)

Free tools — Google Search Console for what people search to find you, your email platform's open/click data, and basic site analytics — tell you what's actually working so you double down instead of guessing. Data beats opinions.

How to choose without overspending

Start free. Every category above has a capable free tier. Don't pay until a tool is clearly making or saving you money.
One tool per job. Resist collecting tools; each new one is overhead.
Adopt for a bottleneck, not for FOMO. If a tool doesn't remove a specific friction you feel weekly, skip it.

The honest bottom line

The best AI stack for a solopreneur is small, mostly free, and pointed at your real bottlenecks: a writing assistant you edit hard, simple design, an all-in-one to run the business, and free analytics to stay honest. Add tools only when a specific pain demands it. The goal isn't to use the most AI — it's to ship more of your best work in less time.

Keep reading

Originally published at tsetsobg.github.io. Some links are affiliate or product links — they never cost you extra.