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 / ResizerResize and re-encode images locally, then compare real file sizes and dimensions.01 · Images & assets
- QR Code GeneratorCreate private URL, text, Wi-Fi, email, telephone and SMS QR codes.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
Changing supported Windows UI font sizes with Font Size Tweak
What the utility changes, how its per-user backup and restore work, and where Windows may ignore the classic font metrics.
- 03
A practical method for testing JavaScript regular expressions
Build a JavaScript pattern in small steps, test edge cases and flags, inspect capture groups, and check replacements before using it.
- 04
Cron Expressions: Syntax, Examples, and Scheduling Notes
Read five-field cron expressions, compare common scheduler differences, and handle time zones and daylight saving deliberately.
05 / The things
More projects
Projects are the work itself. Notes and guides document what happened around them.
Shipped
AstroGenesis.wiki
A browser-based space-bioscience research project: the 2025 challenge diary records a habitability-map prototype, while the linked repository now describes an installable dossier-exploration PWA.
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.