What is App Stack Builder?

App Stack Builder is a free AI-powered tool that helps founders and developers choose the right tech stack for their projects based on budget, app type, team size, and skill level.

What is the best tech stack for SaaS in 2026?

The best tech stack for SaaS in 2026 typically includes Next.js 16 for frontend, Supabase for database and auth, Vercel for hosting, Stripe for payments, and PostHog for analytics. App Stack Builder can generate a personalized recommendation based on your specific budget and requirements.

Is App Stack Builder free to use?

Yes, App Stack Builder is completely free to use. You can generate unlimited tech stack recommendations without any cost.

What types of apps can I build with the recommended stacks?

App Stack Builder supports various app types including SaaS applications, web apps, mobile apps, e-commerce stores, internal tools, and AI/ML products.

How much does a SaaS tech stack cost per month?

A modern SaaS tech stack can cost anywhere from $0-50/month for bootstrapped startups using free tiers, $100-300/month for growth-stage startups, to $500+/month for enterprise-ready infrastructure. App Stack Builder helps you find the best tools within your specific budget.

What is the best tech stack for solo founders?

For solo founders, we recommend Next.js + Vercel (free), Supabase (free tier), Supabase Auth (free), Stripe (pay as you go), and Plausible or PostHog for analytics. This stack can run your entire SaaS for under $50/month.

Can I export my tech stack recommendations?

Yes, you can export your tech stack recommendations as a PDF document or copy them to your clipboard. You can also share a link to your stack with others.

AI Evals & Agent Testing

The 3 Best Ragas Alternatives in 2026

Name: App Stack Builder
Availability: InStock

Looking for an alternative to Ragas? Below we compare the best ai evals & agent testing alternatives by pricing, free tiers, and what each is best for — so you can pick the right fit for your budget and stack.

Why look for a Ragas alternative?

Ragas is a solid ai evals & agent testing choice, but it isn't the right fit for everyone. The most common reasons teams evaluate alternatives:

−Focused on RAG; agent evals still coming
−No hosted dashboard
−LLM-judged metrics cost tokens

Ragas vs Alternatives — Quick Comparison

Tool	Pricing	Free tier	Rating	Best for
RagasYou searched	Free		4.5	AI Evals & Agent Testing — evals, rag
1.DeepEval	Free · paid from $200/mo		4.6	AI Evals & Agent Testing — evals, llm-testing
2.Promptfoo	Free · paid plans by quote		4.6	AI Evals & Agent Testing — evals, red-teaming
3.Coval	From $100/mo	—	4.4	AI Evals & Agent Testing — agent-testing, voice-ai

Top Ragas Alternatives, Explained

1. DeepEval

Free tier4.6· Free · paid from $200/mo

DeepEval lets you write LLM tests the way you write unit tests: assert that an output passes metrics such as answer relevancy, hallucination, tool correctness or task completion, and run them with pytest in CI. It is Apache-2.0 licensed (about 19K GitHub stars) and ships 50+ research-backed metrics, including agent-specific ones. Its maker, Confident AI, hosts results, datasets and tracing: Free for 2 seats and 5 test runs a week, Starter $200/month per organization (unlimited seats, online evals, chat simulations), Team $2,000/month (SSO, SOC 2), and custom Enterprise.

Feels like unit testing, runs in pytest
Agent metrics like tool correctness
Free and open source

DeepEval pricing & review Ragas vs DeepEval

2. Promptfoo

Free tier4.6· Free · paid plans by quote

Promptfoo runs declarative test suites against your prompts, models and agents from the command line or CI, and compares outputs side by side across providers. Its red-teaming mode generates adversarial probes for jailbreaks, prompt injection, PII leaks and harmful output, which is why security teams use it. The core is MIT-licensed (about 26K GitHub stars) and the Community edition is free forever, including 10K red-team probes a month and self-hosting. Enterprise and On-Premise add team sharing, continuous monitoring, SSO and a compliance dashboard at custom prices. OpenAI agreed to acquire Promptfoo in March 2026 and said the open-source project would continue.

Free and open source (MIT)
Best-known red-teaming suite for LLM apps
Config-file tests that run in CI

Promptfoo pricing & review Ragas vs Promptfoo

3. Coval

4.4· From $100/mo

Coval tests voice and chat agents the way self-driving teams test cars: it runs your agent against many simulated callers, personas and scenarios before launch, scores every conversation, then monitors live calls in production with alerts and human review queues. It has a REST API, CLI and MCP server, and states SOC 2 Type II, HIPAA and GDPR compliance. Starter is $100/month (100 simulation minutes, 1,000 monitored calls, $0.40 per extra simulation minute), Growth $500/month (1,000 simulation minutes, 10,000 monitored calls) and Enterprise from $4,500/month. Plans include unlimited seats and a 7-day trial that requires a card.

Built for voice agents, with realistic simulated callers
Testing and production monitoring in one
Published prices and unlimited seats

Coval pricing & review Ragas vs Coval

Frequently Asked Questions

What are the best alternatives to Ragas in 2026?⌄

The best Ragas alternatives in 2026 are DeepEval, Promptfoo, Coval. Each is a ai evals & agent testing option you can compare on pricing, free tiers, and features in the table above.

Is there a free alternative to Ragas?⌄

Yes — DeepEval, Promptfoo offer free tiers, making them strong free Ragas alternatives for bootstrapped startups.

Why look for a Ragas alternative?⌄

A common reason teams switch is focused on rag; agent evals still coming. Beyond that, people compare ai evals & agent testing tools on pricing, specific feature gaps, ease of use, and whether an open-source or free-tier option exists — so they can pick the best fit for their stack and budget.

What is the cheapest Ragas alternative?⌄

DeepEval is among the most affordable Ragas alternatives — free · paid from $200/mo. Check the comparison table above for the full pricing breakdown.

Which Ragas alternative is rated highest?⌄

DeepEval is the highest-rated Ragas alternative in our catalog at 4.6 out of 5, making it a strong pick if you want a well-reviewed option.