DevOkk Blog
How-to articles, category roundups, and fair competitor comparisons for browser-based, privacy-first utilities. Files stay on your device unless a network lookup is the actual job.
Columns, icons-as-headings, and image-only PDFs. What applicant tracking systems actually parse, when a designed resume is fine, and how to keep work history off a career-site account.
7 min read
Code128 vs EAN-13 vs UPC, printers that bleed, guns that expect another symbology. Generate a 1D barcode in the browser - drawing bars is not a GS1 license.
7 min read
XML is a document tree. JSON is typed values. Why converters invent `#text` keys, wrap singles in arrays, and drop namespaces - and how to inspect the result locally.
7 min read
Finder patterns, error correction, logos, and glossy lamination. Generate a scannable code in the browser - a QR is not encryption.
11 min read
Seconds vs milliseconds, UTC vs local, and Excel serial dates. How to convert an instant in the browser without uploading a log dump.
11 min read
Uploading a password-protected PDF to a ‘remove password’ site gives the vendor the file and often the password. When the real job is compress/split locally, and when you still need Acrobat.
15 min read
HTTP pages, mixed content, name-mismatch certificates, and expired TLS. How to tell a padlock problem from a DNS problem without scanning hosts you do not own.
12 min read
Trailing commas, European separators, UTF-8 BOM, and quoted commas. How to get a JSON array without uploading a customer export.
13 min read
Google rewrites title tags from H1s, sitelinks, and brand. How to see the live tags, preview a SERP snippet, and when a rewrite is a bug versus a better click.
13 min read
WebP is fine on the web and hostile in email clients. When to convert to JPG or PNG in the browser instead of uploading Camera Roll to a converter ad.
10 min read
CSP, HSTS, X-Frame-Options, cookies, and noindex - what to look for in HTTP headers, how a header viewer helps, and what it will never prove.
7 min read
Capture, convert PNG/JPG, merge pages, compress - in the browser - so a repro PDF does not upload customer PII to a random converter.
7 min read
You replaced favicon.ico and the old icon is still there. Caches, HTML link tags, SVG vs ICO, and how to generate a new set without an account.
7 min read
Base64 hides nothing. Why people treat it like a cipher, what it is actually for (data URLs, JWTs, APIs), and how to encode or decode in the browser without uploading a key.
7 min read
No Drive, no Dropbox, no ‘anyone with the link.’ How to shrink, split, and email a PDF locally - and when a contracted portal is the real answer.
7 min read
Open Graph caches, relative URLs, 1200×630 crops, and SPA titles. How to see what crawlers see and fix the card without guessing.
7 min read
You updated A or CNAME records but the site still hits the old server. TTL, cache, recursive resolvers, and how to look up public DNS without confusing it with your laptop’s cache.
7 min read
Title tags, meta description, Open Graph, SERP snippet, favicon, bundle weight, lazy-load, and a first accessibility pass - before you ship, without a login.
7 min read
Browser (WASM/JS) conversion keeps the file on the device. Cloud APIs handle OCR, huge files, and 400 formats. How to choose - and what DevOkk actually does.
7 min read
Gmail is 25 MB. Outlook is often lower. How to compress PDFs and images, when to split, and how to stay under the cap without uploading the attachment to a random site.
7 min read
What happens when you upload a contract or ID to a free PDF site. When a browser-local converter is enough, and when you still need Acrobat.
7 min read
JWTs, API keys, customer JSON, and password checkers: a practical list of what to keep off random websites, and which jobs can stay in the browser.
7 min read
HEIC is Apple’s default photo format. Why Paint and older apps reject it, when to convert to JPG or PNG, and how to do it in the browser without an iCloud upload.
7 min read
DevOkk.com is a free, no-account toolkit of 112 browser-based developer utilities. This guide walks through JSON, PDF, image, security, networking, SEO, CSS, calculators, and the rest - including what stays on your device.
13 min read
Shrink a PDF in the browser so it fits Gmail or Outlook limits. No account, no upload to finish the job.
4 min read
Shrink JPG/PNG for faster pages. Compression stays in the browser.
4 min read
Split a PDF by page, range, or interval in the browser. No watermark, no cloud copy to finish the cut.
4 min read
Pick a format for photos, UI, and transparency, then convert locally.
4 min read
A PNG copy of an iPhone photo for editing, done on-device.
4 min read
Make iPhone photos work in apps that reject HEIC, without a cloud album.
4 min read
Remove extra PDF pages in the browser. No Acrobat subscription, no third-party upload.
4 min read
Combine PDFs in reading order in the browser. No Adobe, no cloud locker, no account.
4 min read
Stamp page numbers with position and start index. Processed in the browser, no account.
4 min read
Convert WebP when a CMS or app still wants JPG.
4 min read
WebP to PNG locally for editing workflows.
4 min read
Fix scanned page order in the browser. No cloud copy of the packet.
4 min read
Turn PDF pages into JPGs in the browser for email, chat, and decks.
4 min read
Export PDF pages as PNG when JPEG artifacts smear text. Convert in the browser.
4 min read
Convert JPG to PNG before heavy edits. No upload.
4 min read
Drop huge PNG screenshots to JPG when you do not need transparency.
4 min read
Turn a mixed stack of photos or scans into one PDF in the browser. No account.
4 min read
Rasterize logos and icons to PNG at the size you need.
4 min read
Vector to JPG for email and CMS fields that reject SVG.
4 min read
Turn PDF pages into images on your device. No upload. Choose JPG or PNG for the handoff.
4 min read
Capture a GIF’s first frame as a still image locally.
4 min read
Make a PDF from JPG photos in the browser. No install, no account.
4 min read
Bundle PNG screenshots into one PDF in the browser. No account, no upload to finish the handoff.
4 min read
Thumbnail and poster type-behind-subject effects in the browser.
4 min read
Read public DNS records to debug domains. Lookups send the hostname to resolve them.
5 min read
Title, description, canonical, and robots - extract and review before launch.
4 min read
Write and export a resume without uploading work history to SaaS.
6 min read
Pick primaries, tints, and contrast-safe pairs in the browser.
4 min read
Use a = Δv / t with worked problems. Run the numbers locally in a browser calculator.
4 min read
Average velocity problems for class and lab. Calculate in the browser with unit care.
4 min read
Convert metres, feet, inches, and miles accurately in the browser.
4 min read
Temperature scales with the right formulas and a local converter.
4 min read
Freelance invoices in the browser; client data stays local.
5 min read
Tree view tactics for large payloads.
4 min read
Resolve a hostname to A/AAAA addresses for debugging.
4 min read
Pretty-print and catch syntax errors locally after a messy paste.
4 min read
High-entropy passwords generated on-device. Nothing sent to a server.
5 min read
Header, payload, signature - decode locally so tokens never hit a website.
5 min read
Keyframes, easing, and reduced-motion - preview before you paste into a codebase.
4 min read
og:title, og:image, and twitter cards - preview before you post.
4 min read
QR basics and local generation for URLs, Wi-Fi, and vCards.
5 min read
TLS basics and a public certificate check. The hostname is sent to complete the lookup.
4 min read
Newton’s second law with examples. Local force calculator for physics homework and checks.
4 min read
KE = ½mv² explained, with unit conversion notes and a browser calculator.
4 min read
Strength analysis in the browser. The password is not stored or transmitted.
4 min read
SI vs binary prefixes for storage. Convert locally while debugging downloads.
4 min read
Seconds vs milliseconds, UTC vs local, converted in the browser.
4 min read
Shareable profile cards with no design subscription.
5 min read
Strip whitespace locally before you ship.
4 min read
Cache, cookies, CORS, and security headers from a live response.
4 min read
Nested JSON as an interactive graph in the browser.
4 min read
Hashing vs encryption, collisions, and local checksums.
5 min read
Density formula, units, and lab-style examples you can compute in the browser.
4 min read
Gravitational potential energy problems and a local calculator for classwork.
4 min read
Spreadsheets to JSON arrays, locally.
4 min read
Speed conversions for class, travel, and physics checks.
4 min read
Naming conventions and headlines, converted locally.
4 min read
Legacy XML to JSON without an upload.
4 min read
Percent-encoding and query params, decoded locally while debugging.
4 min read
Data URLs, tokens, APIs - encode and decode privately.
5 min read
Barcode types and on-device labels.
5 min read
ICO, PNG, Apple touch, and SVG favicons from one source image.
4 min read
What ping measures, what it does not, and how to read the result.
4 min read
SERP length, intent, and a snippet preview before you ship.
4 min read
Mass and weight are not the same. Convert each family with the right tool.
4 min read
PTR lookups map IPv4 to a hostname. The address is sent to perform the lookup.
4 min read
Accessible names, contrast, and structure checks you can run while you build.
4 min read
Lazy-load vs LCP trade-offs, with a browser tester for your markup.
4 min read
Headings, labels, and alt text as a screen reader would announce them.
4 min read
Watts, horsepower, and P = IV / P = W/t. Browser calculator for engineering checks.
4 min read
P = F/A with real examples. Calculate locally.
4 min read
Joules, calories, watts, and horsepower without mixing energy and power.
4 min read
CMS HTML to Markdown without sending drafts out.
5 min read
Tire gauges, labs, and weather maps use different pressure units.
4 min read
YAML configs to JSON for tools that only accept JSON.
4 min read
Entity encoding for safe HTML display.
5 min read
Preview embedded bitmap arrays in the browser.
4 min read
Titles, canonicals, FAQs, and internal links that help a tool site rank.
4 min read
Pick a UUID version and generate IDs locally.
5 min read
Placeholder text for mockups, generated locally.
4 min read
Resume, invoice, PDF, and image steps that stay local.
5 min read
Molarity formula, worked lab examples, and a local calculator for solution prep.
4 min read
Pixels to arrays for embedded work.
4 min read
m², litres, and kg/m³ conversions that stay consistent.
4 min read
Number bases for debugging and coursework, converted on-device.
4 min read
Avoid DST mistakes with a local timezone converter.
4 min read
Test regex against real strings in the browser.
5 min read
Rearrange PV = nRT, watch units, and solve for unknowns locally.
4 min read
Org charts, file trees, and nested JSON as a tree you can inspect locally.
4 min read
US MPG, UK MPG, and L/100km are not the same formula.
4 min read
EXIF GPS, authors, software tags - inspect before you share.
5 min read
Heatmaps for layouts and click hypotheses - simulate patterns without analytics export.
4 min read
Metadata, PDFs, and cloud converters: a local-tool checklist.
5 min read
Sum atomic masses correctly and check the result with a browser molecular weight tool.
4 min read
Common parse errors and a local formatter once it is valid.
4 min read
Strip location and author data in the browser.
5 min read
Pick a format, then convert locally when you need another shape.
4 min read
When chemists use molality vs molarity, plus local calculators for both.
4 min read
pH, pOH, and strong-acid approximations with a local pH calculator.
4 min read
Stock-to-working concentration math for labs. Dilute locally with a calculator.
4 min read
