Software Alternatives & Startups

Sunasty VS Diffyn

Compare Sunasty VS Diffyn and see what are their differences

Sunasty

130+ free file tools that run entirely in your browser. No upload, no account.

Rating
0 reviews
Diffyn

The modern platform for creating, sharing, and collaborating on AI prompts. Advanced version control and real-time testing.

Rating
0 reviews
Pricing
Freemium $9.99 / Monthly (Starter)

Which is more popular?

Based on our record, Sunasty seems to be more popular. It has been mentioned 1 time since March 2021.

social mentions
1 vs 0
PDF Tools popularity
100% vs 0%

Base details

Website, pricing, platforms and company facts side by side.

Sunasty
Diffyn
Website sunasty.com diffyn.com
Pricing —
Freemium $9.99 / Monthly (Starter)
Platforms
Windows Android iOS MacOS Mobile Desktop +3
Browser
Company Startup from France · 1 - 9 employees · 2026 —
Listed in

About Sunasty and Diffyn

In their own words, as submitted to SaaSHub.

Sunasty
Diffyn

Sunasty is a suite of 130+ free utilities for everyday file tasks: PDF (merge, split, compress, sign, unlock), images (compress, resize, crop, redact, HEIC to JPG), video and audio (compress, convert, trim, extract audio, screen recording), plus developer, date and calculator tools. The...

Read more about Sunasty

No description of Diffyn yet.

Features and specs

What each product offers, as listed by its team.

Sunasty 10 features
Diffyn 3 features
  • 100% in-browser processing
    Every tool runs locally via WebAssembly (FFmpeg, qpdf, MozJPEG/OxiPNG/WebP/AVIF codecs). Your files never reach a server: there is nothing to upload, leak or delete.
  • 130+ tools in one place
    PDF, images, video, audio, converters, developer utilities, date tools, calculators and QR codes, all under one roof with a consistent interface.
  • No account, no quotas
    No sign-up, no daily limits, no file size tiers, no premium plan.
  • Works offline
    Once a tool's page has loaded, it keeps working with the connection cut. Installable as a PWA.
  • Full PDF suite
    Merge, split, compress (lossless or strong), organize, rotate, sign, protect, unlock with a known password, watermark, page numbers, OCR and more.
  • Smart image compression
    Pick a quality or a target size in KB, convert between JPEG, PNG, WebP and AVIF, process whole batches at once.
  • Video & audio toolbox
    Compress and convert video, trim, mute, extract audio to MP3/WAV/AAC/OGG, GIF in both directions, plus local screen, webcam and voice recorders.
  • Verifiable privacy
    Open DevTools' network tab while using any tool: no request ever carries your file. Re-encoding strips EXIF metadata (including GPS).
  • 28 languages
    Fully localized, including right-to-left Arabic. Guides even show screenshots of the tools in your own language.
  • Honest by design
    Illustrated guides, transparent competitor comparisons, and clear notes about what a browser cannot do faithfully.
  • Version Control
    Manage changes with visibility on all versions to enhance traceability for prompt for teams and professionals.
  • Visualization
    Side-by-Side Viewer with diff highlighting on changes made and comparison of outputs across different LLM models.
  • Advanced Analytics
    OpenAI powered assistant to provide analyisis on the test outputs and improvment. Gemini powered evaluation on cost efficiency, readability metrics

Analysis

An editorial look at what each product does well and who it suits.

Sunasty
Diffyn

Overall verdict

  • There is no reliable public information available about Sunasty (sunasty.com), so it is not possible to confirm whether it is a good or trustworthy service. Exercise caution and do your own research before using it.

Why this product is good

  • Limited or no verifiable information about the company, its ownership, or its track record is publicly available
  • Lack of established reviews or reputation makes it difficult to assess reliability and trustworthiness
  • Before sharing personal or payment details, it's wise to verify security practices, contact information, and return/refund policies
  • Checking independent review platforms and community feedback can help confirm legitimacy

Recommended for

  • Users who have independently verified the site's legitimacy and security
  • Customers who proceed cautiously with small test transactions first
  • Those who have confirmed clear contact, refund, and privacy policies before purchasing

Overall verdict

  • I don't have verified, up-to-date information about Diffyn (diffyn.com) to make a confident assessment of its quality, features, or reliability. I'd recommend researching directly through the website, checking independent reviews, and testing any free trial before committing.

Why this product is good

  • I don't have reliable data on this specific product to list genuine advantages.
  • Product offerings and quality can change over time, so real-time verification is important.
  • Independent user reviews, G2/Capterra ratings, or trusted tech publications would provide more accurate insight.

Recommended for

  • Users who verify through independent research before adoption.
  • Those who prioritize checking recent reviews and testing free trials.
  • Anyone needing current, verified information rather than assumptions.

Videos

Walkthroughs and reviews on video.

Sunasty 0 videos + Add
Diffyn 1 video + Add

No Sunasty videos yet. You could help us improve this page by suggesting one.

The Ultimate Prompt Tool for Creators – Visualize & Organize with Diffyn

Category popularity

How often each product is chosen within a category, 0–100% relative to the other.

Score bands 0–20 21–40 41–50 51–60 61–100
Sunasty
Diffyn
100% 100%
0% 0%
54% 54%
46% 46%
100% 100%
0% 0%
0% 0%
100% 100%

Questions & Answers

As answered by people managing Sunasty and Diffyn.

What makes your product unique?

Sunasty's answer

The privacy is structural, not a policy promise: every tool runs entirely in your browser through WebAssembly, so your files never leave your device. You can verify it yourself by opening the DevTools network tab while using any tool: no request carries your file, and everything keeps working offline once the page has loaded. Combined with 140+ tools, no account, no quotas and 28 languages, that architecture is the product.

Diffyn's answer:

Addresses workflow and change management on LLM prompts, provide teams with traceability and visualization of tests across multiple models, provide deeper understading into efficiency of these prompts.

Why should a person choose your product over its competitors?

Sunasty's answer

Most popular alternatives (iLovePDF, Smallpdf, CloudConvert, TinyPNG) process files on their servers and monetize through limits: daily quotas, file size caps, subscriptions. With Sunasty there is no upload wait, no copy of your document on someone else's machine, and no counter to unlock, because the work happens on your own hardware. And when a competitor genuinely is the better choice (for example server-side conversion of PDF to editable Word, which a browser cannot do faithfully), our comparison pages say so.

Diffyn's answer:

Diffyn is the platform that specializes on both change management and multi-model analysis.

Which are the primary technologies used for building your product?

Sunasty's answer

The site is statically generated with Astro and TypeScript, with lightweight Preact islands for interactivity. The heavy lifting runs client-side in Web Workers through WebAssembly builds of proven engines: FFmpeg for video and audio, qpdf and pdf-lib for PDF, the Squoosh codecs (MozJPEG, OxiPNG, WebP, AVIF) for images, and Tesseract for OCR. There is no application backend at all: the server only delivers static files.

Diffyn's answer:

React, Next.js, POSTGRESQL

How would you describe the primary audience of your product?

Sunasty's answer

Anyone who handles files day to day: people compressing a PDF to fit an application portal or an email cap, gamers and creators trimming and shrinking clips for Discord, anyone blurring a name on a screenshot before sharing it, developers formatting JSON or testing regexes, and privacy-conscious users working with contracts, IDs or anything confidential that should never transit through a third-party server.

Diffyn's answer:

Professionals incorporating LLMs or AI tools in their workflow and wants to keep track of changes and test their prompts.

What's the story behind your product?

Sunasty's answer

Sunasty is built by a solo developer in France. The trigger was a familiar frustration: every "free" online tool for a 30-second file task wanted an upload to an unknown server, an account, or a subscription to lift an artificial limit. Modern browsers can do that work themselves thanks to WebAssembly, so Sunasty was built the other way around: the file never leaves your device, by architecture. The amber cat in the logo is the developer's actual cat.

Diffyn's answer:

I started working on Diffyn when I notice that prompting has become an essential part of work across many industries. While there are version control platofrms like github, they are not designed for just prompt management are can be overkill such applications, it is also not integrated natively with various LLMs and relevant tools for users to validate ideas and visualise results properly.

Who are some of the biggest customers of your product?

Sunasty's answer

Sunasty is a free consumer tool, so there are no enterprise contracts to name, and since there are no accounts and files never reach us, we genuinely cannot tell who uses it. It is used by individuals worldwide in 28 languages, which is exactly how a privacy tool should work.

User comments

Share your experience with using Sunasty and Diffyn. For example, how are they different and which one is better?

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Social recommendations and mentions

Recommendations tracked on public social media and blogs since March 2021.

Sunasty 1 mention
Diffyn 0 mentions
  • Show HN: I built 184 free browser tools – PDF, image, dev, AI tasks, no upload
    Have you checked out https://sunasty.com. - Source: Hacker News / 4 months ago

Tracking Diffyn since Jun 2025.

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