Quick browser tools — no signup, nothing uploaded. When you need batch, offline, or unlimited power, the matching Kaizen desktop app takes over.
Measure your clicks per second in 1–100 seconds. Spacebar mode and the Kohi 10-second test included.
Combine JPG & PNG images into a single PDF, in order, right in your browser. Private — nothing uploaded.
Combine multiple PDFs into one, in your chosen order — right in your browser. Private, nothing uploaded.
Extract chosen pages or split a PDF into separate files — in your browser, nothing uploaded.
Convert every PDF page to a JPG image, then download them individually or as a ZIP. Private.
Shrink JPG, PNG & WebP images with a quality slider — see the savings live. Nothing uploaded.
Rotate PDF pages 90°, 180° or 270° and save — all pages or selected ones. Private, in your browser.
Change image dimensions by pixels or percent, keeping aspect ratio. Batch + ZIP. Nothing uploaded.
Crop photos with a draggable selection and aspect presets, then download. Private, in your browser.
Convert every PDF page to a crisp PNG image, then download individually or as a ZIP. Private.
Convert images between PNG, JPG and WebP in your browser — batch + ZIP. Nothing uploaded.
Shrink a PDF's file size right in your browser — private, nothing uploaded. Heavy or sensitive files? Kaizen OCR & PDF does it offline.
Remove pages from a PDF in your browser — pick them visually or by range. Private, nothing uploaded.
Number your PDF pages with custom position, format and start value. Private, in your browser.
Extract text from an image in your browser. For 4-engine accuracy, 100+ languages & batch jobs, use Kaizen OCR.
Type text and hear it read aloud in your browser. For 700+ AI voices & MP3 export, use Kaizen Speech Studio.
Live word, character, sentence & paragraph counts plus reading time — instant, private, no signup.
Count spacebar presses freely or race the clock in 5–60s modes. Presses per second, instantly.
Measure right-clicks per second over 5–30s — the bridging-practice favourite.
Count double-clicks per second — and catch a faulty mouse that double-clicks on its own.
The classic 10-second Minecraft CPS benchmark with authentic Kohi ranks.
Measure jitter CPS with burst and consistency stats — how stable is your shake?
Two fingers, one button — measure butterfly CPS and your best 1-second burst.
Spin the wheel or swipe — measure pixels scrolled and speed per second.
Wait for green, click fast — reflex speed in milliseconds over 5 rounds.
Live character, word, sentence & line counts with X, Instagram, SMS and SEO limit checks.
UPPER, lower, Title, Sentence, camelCase, snake_case, kebab-case — one click each.
Fix PDF/email-copied text: join broken lines, keep paragraphs, collapse spaces.
Replace across pasted text with live counts — case, whole-word and regex modes.
Repeat text or emoji N times with separators and numbering — copy in one click.
Turn titles into clean SEO-friendly URL slugs — accents, stop words and symbols handled.
Placeholder paragraphs, sentences or words — classic opening optional, copy in one click.
Pull audio from video. For dubbing, transcription and YouTube tools, Kaizen Speech Studio does it all.
More tools ship every week. Want one prioritised? Tell us.