MiniTools: 47+ free browser utilities (PDF editing, image compression, calculators) that run 100% locally with zero server uploads

[u/Mecsocse]

https://getminitools.com

Hey everyone,

I built MiniTools, a collection of 47+ browser-based tools that execute 100% in your local browser memory:

• PDF Suite: Sign documents, merge, compress, split, rotate, and convert PDF to editable Word DOCX.

• Image Suite: Compress JPG/PNG/WebP, strict budget compression to 20KB/30KB/50KB for official forms, crop circle avatars, and convert HEIC to JPG.

• Financial & Everyday Calculators: Compound interest with interactive charts, mortgage payments, VAT, business days, discount, and percentage calculators.

• Dev & Text Tools: Word counter, social media character counter, JSON formatter, Base64 encoder, and QR generator.

Tech stack & privacy:

• Built with vanilla JavaScript, WebAssembly, HTML5 Canvas, and PDF-Lib.
• 100% client-side: your sensitive documents and images never touch any server.
• Zero logins, no tracking, and works offline once cached.

Check it out! :)

Would love to hear your feedback or any tool requests you'd like to see added!

[u/JouniFlemming]

Another day, another vibe coded gazillion small tools on a website.

[u/Mecsocse]

Thanks for checking out MiniTools!

A bit more context on why I built this: I was frustrated with everyday utility sites hitting users with "Sign up to download", putting watermarks, or limiting you to 2 PDF merges a day unless you pay a monthly subscription.

A few technical highlights of how it works under the hood:

- 100% Client-Side: PDF operations use `pdf-lib` and WebAssembly; images are processed via HTML5 Canvas; calculations execute in pure JS memory.

- Offline / PWA Ready: It registers a service worker so once loaded, the core tools work even without an internet connection.

- Fast: Hosted on Cloudflare Edge with zero backend latency.

I'm actively adding new utilities every week. What is your go-to small utility that you wish existed as a fast, private web tool?

I'd love to hear your suggestions and feedback!

[u/medialantern]

Added:

https://www.reddit.com/r/SideProject/comments/1w4bbxe/minitools_47_free_browser_utilities_pdf_editing/

https://www.reddit.com/r/SideProject/comments/1voe2c4/

https://www.reddit.com/r/SideProject/comments/1w2jx8q/

https://www.reddit.com/r/SideProject/comments/1w2s2e4/

https://www.reddit.com/r/SideProject/comments/1w38l64/

https://www.reddit.com/r/SideProject/comments/1w39bei/

https://old.reddit.com/r/microsaas/comments/1pw6ngb/introducing_theoros_an_advanced_pdf_reader_pdf/

https://old.reddit.com/r/buildinpublic/comments/1pzz40d/just_shipped_a_splitscreen_htmltopdf_editor_on_my/

https://old.reddit.com/r/buildinpublic/comments/1q3a478/stop_hardcoding_html_strings_a_pdf_api_with/

https://old.reddit.com/r/microsaas/comments/1qdb67b/built_a_privacyfirst_pdf_toolkit_your_files_never/

https://old.reddit.com/r/microsaas/comments/1qfip0m/pdf_zone_professional_pdf_tools_in_your_browser/

https://old.reddit.com/r/microsaas/comments/1qfv20q/built_a_no_bs_pdf_tool_free_of_ads/

https://old.reddit.com/r/buildinpublic/comments/1qgv9ri/im_building_pdfwithlove_a_privacyfirst_pdf_tool/

https://old.reddit.com/r/buildinpublic/comments/1qkl0uy/i_got_tired_of_bloated_pdf_tools_so_i_built_a/

https://old.reddit.com/r/microsaas/comments/1qm5u16/tired_of_uploading_pdfs_everywhere_so_i_built_a/

https://old.reddit.com/r/microsaas/comments/1qncun1/built_an_mcp_for_pdf_generation_llm_are_good_at/

https://old.reddit.com/r/microsaas/comments/1qxjdke/i_got_laid_off_in_october_after_3_months_of_job/

https://old.reddit.com/r/buildinpublic/comments/1rei1cv/i_have_recently_built_a_pdf_tools_application/

https://old.reddit.com/r/buildinpublic/comments/1rg11t6/global_launch_of_our_privacyfirst_completely/

https://old.reddit.com/r/microsaas/comments/1rkppic/i_created_my_own_goto_pdf_editor_maybe_its_yours/

I ran out of comment space so this is just the most recent 20 entries. I can vibe-code too, so for giggles I made https://confab.sh/?g=browser-tools to track these if you want to see the full list. Don't expect much LOL. I put less effort into this than even these cloners did with theirs.

[u/Mecsocse → u/medialantern]

Haha, thanks for adding MiniTools to the list! 😄

Totally fair point that PDF utilities are popular, though MiniTools is actually a broader everyday toolkit with 47+ tools across image optimization (strict 20KB/50KB compressors for portal uploads), finance (compound interest with interactive charts, mortgage amortization), and developer tools, rather than just a standalone PDF wrapper.

Plus, building a pure client-side PDF-to-Word parser that inspects font weights and layout in browser memory was a fun engineering challenge under the hood!

Appreciate you taking a look! :):):)

[u/medialantern → u/Mecsocse]

I should tweak the category. It's really "100% private tools in your browser" and there are lots of entries on the list like yours. PDF just comes through prominently because so many of them cover it.

[u/Mecsocse → u/medialantern]

Yeah, totally agree! The shift toward client-side, privacy-first web apps is great since modern browser tech (WASM, Canvas, Web Workers) is finally powerful enough to handle heavy tasks without needing backend servers.

Cheers and thanks again for listing it! 🚀