Browser tool
Image Converter & Resizer
Resize and convert JPG, PNG, WebP, HEIC, and HEIF images to WebP, AVIF, or JPEG XL without uploading them.
Useful for: Preparing phone photos and transparent images for blogs, websites, and other web projects.
A place to explore and create
Wataru’s Web Lab
I'm a frontend engineer, an artist, a husband and a dad. I've worked on data-intensive B2B applications in fields including cybersecurity, data science. I studied art before finding my way into frontend development, and I enjoy working on both the visual details and the business logic behind an interface.
I use this site to keep notes on what I've learned, share my two cents and work out what I want to learn next. I write about JavaScript and React, including questions I've worked through about state management and handling API requests. I write about traveling in Japan with my kids, too. Through these notes and the things I make, I explore how art, technology and my life fit together.
Tools
Focused tools you can use directly in your browser.
Browser tool
Background Remover & Image Cutout
Remove backgrounds from JPG, PNG, HEIC, WebP, AVIF, or JPEG XL images and export a transparent result.
Useful for: Creating product cutouts, profile images, stickers, and transparent assets for websites.
Browser tool
Image Upscaler
Enlarge JPEG, PNG, WebP, and AVIF images by 2× to 8× with Pica interpolation and light sharpening.
Useful for: Making small images larger without uploading them or generating imaginary detail with AI.
Browser tool
Mandala Mind Map
A private 9×9 mind map for article ideas, brainstorming, project planning, and goals.
Useful for: Explore a main idea through up to eight themes and 64 details: ideas, questions, notes, or actions.
Browser tool
Micro Habit Development Sheet
Build a printable 22-day tracker for one small habit, with room for up to three daily actions.
Useful for: Making a tiny action visible and marking each day with checks, colors, or stickers.
Browser tool
Text to Image Generator
Turn multiline text into a polished square, portrait, or landscape image with local Canvas export.
Useful for: Creating social graphics for Twitter / X, Pinterest, Facebook, Instagram, and TikTok.
Browser tool
JSON, YAML, TOML & Query String Converter
Convert structured data between JSON, YAML, TOML, and nested Query Strings in either direction.
Useful for: Moving API payloads, configuration data, and search parameters between formats without uploading them.
Browser tool
Word Counter & Frequency Analyzer
Count words in real time, rank repeated terms, and highlight every exact occurrence in your draft.
Useful for: Reviewing repetition and word choice without uploading or saving the text.
I build and share tools I want to use to solve problems I run into. Making a birthday poster for my child got me experimenting with browser-based image tools; our sticker charts at home inspired a printable habit tracker for adults. You can use the image tools without an account or uploading your photos. I make word and number games, and experiment with color and motion in studies like AutoMata. I'm curious about how much I can make on a single web page, whether it's something useful or something to play with.
The opinions expressed on this site are my own and do not reflect the views of any other person or organization.
I use AI to help with development and editing. English is not my first language, so I use it to correct my grammar, too. I plan, think things through, organize my ideas, and write in English. I make the final decisions and take responsibility for what I publish here.
Things I’d Rather Not Forget
Build notes, technical lessons, travel, parenting, and other things worth keeping.
Games
Quick browser games with no signup required.
Word game
LEXAGON
Close word circuits from four sides to twelve by placing each missing letter in the glowing loop.
Good for: A tactile word puzzle where every completed edge powers the next side of a growing polygon.
Number game
Arithmix
Hunt through a luminous number grid and solve rapid-fire arithmetic prompts before time runs out.
Good for: A fast, tactile number hunt spanning mental arithmetic and prime numbers.
Number game
Sort Break
Race through Bubble Sort one comparison at a time. Definitely not interview prep.
Good for: A tiny sorting brain break with guided comparisons.
Word game
Daily Anagram
Unscramble ten familiar words and track completed numbered puzzles in your browser.
Good for: A quick word challenge with hundreds of selectable puzzle sets.
Word game
Anagram Solver
Enter 3–12 letters and find exact English anagrams, with common words shown first.
Good for: Checking a letter mix or exploring alternate arrangements.
Creative
Creative coding, visual experiments, and interactive studies.
Fluid study
Red Ink
Translucent red ink folds into fine threads and slowly drifts through clear water.
Coding study
AutoMata
A color-field study in which neighboring cells evolve together through flocking-like rules.
3D study variation
Kira Kira 3D
The color-flocking logic of AutoMata, expanded into a three-dimensional field of points.
Coding study variation
AutoMata: Red Field
A living field of red, crimson, magenta, and pink circles that breathe with their neighbors.
Study variation
Angle Field
A field of small lines turns with its neighbors while the background drifts through color.