355+ Free Online Tools — SEO, PDF, Image & Developer

355+ free browser utilities for SEO, PDF, image editing, finance and developers — no signup, no uploads, privacy-first. Made in Utrecht, NL.

Techtter Tools is a privacy-first catalog of 355 free utilities that run in your browser. We built it for SEO specialists, developers, founders, and operators who need dependable one-off tasks—sitemap audits, PDF merges, image compression, text cleanup, security checks, and everyday calculators—without installing desktop software or creating another SaaS account. Each tool has its own stable URL, FAQs, and structured data so you can bookmark, link internally from blog posts, and submit individual pages to Search Console. Files stay on your device for typical workflows; only tools that explicitly document a server step (for example, a public TLS probe) call our API. Browse the categories below, use the tabs to filter the grid, or search by name. Techtter Solutions B.V. (Utrecht, Netherlands, KvK 91402182) maintains the hub alongside our AI and software delivery work—open a category to see every tool in that group. PDF & document tools: Merge, split, compress, sign, and convert PDFs without uploading files to our servers. Edit pages, run OCR, fill forms, export to Word or images, and batch-process archives for publishing workflows. SEO & web tools: Audit crawl health with sitemap checkers, validators, and broken-link probes. Draft meta tags, preview SERP snippets, extract on-page links, and brainstorm keyword lists before you ship content. Image tools: Resize, compress, crop, and convert formats in the browser. Remove or blur backgrounds, build memes and banners, read EXIF metadata, and export avatars or social crops without a desktop editor. Video tools: Trim, resize, crop, and convert MP4, WebM, and MOV in the browser with FFmpeg—no upload to our servers. Burn subtitles, change speed, merge clips, export GIFs, and pull still frames for social posts. Text & Markdown tools: A large Text Tools suite for case changes, cleaning, encoding, and generation—plus PDF and HTML to Markdown converters for docs, CMS paste-ins, and technical writing pipelines. Developer tools: Format JSON and XML, decode JWTs, test regex with replacements, build cURL commands, hash strings, generate UUIDs, and inspect HTTP status codes—handy during API integration and code review. Security tools: Generate strong passwords, score strength locally, hash with MD5/SHA families, work with bcrypt, and peek at public TLS certificates—useful for demos, support, and quick sanity checks. Math & number tools: Percentages, primes, GCD/LCM, Roman numerals, Fibonacci sequences, GPA helpers, and a full calculator—ideal for homework checks, spreadsheets, and quick what-if math. Unit converters: Convert length, area, volume, weight, speed, temperature, and data-storage units with SI-friendly constants. Handy for international specs, recipes, and infrastructure sizing. Date & time tools: Days between dates, age calculators, countdowns, Pomodoro timers, time zones, Unix timestamps, and work-hour math—everything stays in your local clock unless a page notes otherwise. Finance & business tools: Loan EMI, compound interest, ROI, margins, VAT checks, invoices, payslips, and salary conversions for founders, freelancers, and ops teams who need fast numbers without a spreadsheet. Everyday utilities: BMI and macro calculators, QR codes, tip splits, pregnancy due dates, fuel costs, CSS gradients, and other small helpers you reach for dozens of times per month. Fun & creative extras: Spin wheels, roll dice, flip coins, run typing tests, and generate playful names or palettes when you want a break—or quick assets for social posts and prototypes. Techtter publishes long-form guides on the blog and offers consulting when you need integrations, SLAs, or secure hosting beyond interactive demos.

Browse by category

PDF & document tools

Merge, split, compress, sign, and convert PDFs without uploading files to our servers. Edit pages, run OCR, fill forms, export to Word or images, and batch-process archives for publishing workflows.

Popular: PDF merger · Compress PDF · PDF to Word

Video tools

Trim, resize, crop, and convert MP4, WebM, and MOV in the browser with FFmpeg—no upload to our servers. Burn subtitles, change speed, merge clips, export GIFs, and pull still frames for social posts.

Popular: Video to MP4 · Video cutter · Video to GIF

Developer tools

Format JSON and XML, decode JWTs, test regex with replacements, build cURL commands, hash strings, generate UUIDs, and inspect HTTP status codes—handy during API integration and code review.

Popular: JSON formatter · JWT decoder · Developer hub

All free online tools (355)

Frequently asked questions

What are the best free SEO tools online?
Techtter’s SEO & web category on this hub covers sitemap generation, validation, URL extraction, HTTP status checks, robots.txt, meta tags, SERP previews, broken-link probes, and keyword helpers—355 tools total across the catalog, all free in the browser. Start with /tools/sitemap-validator and /tools/sitemap-checker before submitting to Search Console; use /tools/robots-txt-generator and /tools/meta-tag-generator when you ship new templates.
What is the best free sitemap validator online?
For XML syntax and sitemap.org protocol rules before crawlers ignore your file, use Techtter’s Sitemap Validator at /tools/sitemap-validator—paste XML or a public sitemap URL in your browser. Pair it with the Sitemap Checker at /tools/sitemap-checker so you validate structure and confirm each loc returns HTTP 200.
What free PDF tools can I use without uploading to the cloud?
The PDF & document category includes merge, split, compress, sign, rotate, watermark, OCR, form fill, and export to Word, JPG, or Markdown—typically processed locally with Web APIs so files are not stored on Techtter servers. Try /tools/pdf-merger, /tools/pdf-compress, /tools/pdf-splitter, and /tools/pdf-to-word; browse /tools/pdf-editor and /tools/pdf-toolbox for more workflows.
Can I compress a PDF without losing quality?
Truly lossless shrink is rare for scan- or slide-heavy PDFs. Techtter’s PDF Compress at /tools/pdf-compress re-encodes pages as JPEG with adjustable quality sliders—you trade a small amount of sharpness for smaller files, while pure text PDFs may barely change size and can lose selectable text. Preview the download before sharing.
How do I resize or compress images online for free?
Use Techtter’s image and video tools to resize dimensions, compress JPEG/PNG/WebP, crop, convert formats, remove backgrounds, and build memes or banners in the browser—no desktop editor required. GIF workflow: /tools/gif-maker, /tools/gif-analyzer, /tools/gif-to-mp4, /tools/gif-to-webm, /tools/gif-to-mov, /tools/webp-to-gif, and related *-to-gif converters; video: /tools/video-resizer, /tools/video-cropper, /tools/video-cutter, /tools/video-to-mp4, /tools/video-to-gif.
What free developer tools work in the browser?
The developer category covers JSON and XML formatters, JWT decode, regex testers, cURL builders, hash and UUID generators, Base64, and HTTP status helpers—handy during API integration without installing CLI utilities. Open /tools/json-formatter, /tools/jwt-decoder, or /tools/developer-tools for the full set; inputs stay in your session unless a page documents a server fetch.
Where can I find free text and Markdown tools online?
Techtter lists a large Text Tools suite at /tools/text-tools for case changes, cleaning, encoding, counters, and generators, plus standalone converters such as /tools/html-to-markdown and /tools/pdf-to-markdown for CMS and docs workflows. Each tool has its own URL, FAQs, and structured data for search and answer engines.
How do I check if every URL in my sitemap returns 200?
Use the free Sitemap Checker at /tools/sitemap-checker: enter your public sitemap.xml or index URL and it requests each loc to report status codes, redirects, and errors. Only URLs you provide are fetched from your session—we do not build a permanent crawl index of your site.
Are Techtter’s online tools free with no account?
Yes. This hub lists 355+ free browser utilities—SEO, PDF, image, text, developer, security, math, finance, and more—with no paid tier or signup for typical use. Open any tool URL, run the task, and copy or download results immediately.
Where is my data processed when I use Techtter Tools?
Most PDF, image, text, and calculator tools run entirely in your browser. SEO utilities that check a remote sitemap or page only request URLs you enter—see each tool page for whether a server hop is documented. Clear the tab after sensitive work; no account is required for standard free use.