Active project
404cache
An independent digital workshop for useful browser tools, documented projects, and practical technical writing.
Open the project- Built with
- Next.js
- Contentlayer
- Cloudflare
Independent digital workshop
Useful tools and honest notes from building things on the web.
404cache is Adam Johnston’s workbench for browser-based tools, documented projects, practical technical guides, and the useful bits learned along the way.
Build things.
Learn things.
Document the useful bits.
01 / Use something
Featured tools
Small browser utilities for the jobs that should not need an account, an upload, or a complicated workflow.
- Image Compressor / ResizerCompress & resize images in your browser. Strip metadata, set quality & dimensions.01 · Images & assets
- QR Code GeneratorTemporarily unavailable while QR output is being repaired and verified.02 · Images & assets
- Regex TesterLive highlight, capture groups & replace. Copy matches as JSON/CSV.03 · Text & data
02 / In progress
Currently building
The active work, shown with its decisions and rough edges rather than presented as a finished case study.
03 / Build notes
From the workbench
Technical decisions and lessons recorded while making and maintaining things.
Build note / 2026
Why 404cache is built for Cloudflare Pages
The hosting decision behind 404cache: a static Next.js export, Cloudflare delivery, and the boundary around server-side features.
Build note / 2026
What GitHub Actions actually automates for 404cache
A grounded look at the three workflows in the repository, including their permissions, limits, and deliberately manual steps.
04 / Keep for later
Practical guides
Focused explanations for problems you can solve, reuse, and adapt.
- 01
Robots.txt and sitemaps: a practical publishing guide
What each file can and cannot do, how 404cache generates them, and a safe checklist for publishing your own.
- 02
Mastering Regular Expressions: Build Your Own Regex Tester
Learn regex fundamentals and build a lightweight regex tester with JavaScript and HTML.
- 03
Cron Expressions Guide: Automate Tasks Like a Pro
Learn to read and build cron expressions to schedule recurring tasks on Linux, Node.js and cloud platforms with practical examples.
05 / The things
More projects
Projects are the work itself. Notes and guides document what happened around them.
Shipped
AstroGenesis.wiki
An interactive habitability map that turns NASA space-bioscience research into explorable insight cards.
Shipped
FontSize Tweak
A portable utility for changing individual Windows interface font settings.
06 / About
A digital workshop, not a content factory.
404cache is the home of tools, technical writing, experiments, and project documentation by Adam Johnston. It exists to build useful things, document the process, and preserve what was learned.