Eva vs Heptabase

Eva and Heptabase are both productivity tracked by AIDiveForge. Below is a side-by-side comparison of pricing, capabilities, platforms, and ownership — sourced from each tool's live website and verified before publishing.

Eva

The home screen organizes work across four tabs — Chat, Images, Music, Docs — so you are not stitching together separate apps to get a grounded assistant plus media playback. Music continues in the background with lock-screen controls while you use the chat or docs tabs, which means the assistant does not interrupt your queue. The ceiling appears fast on older or mid-range hardware: on-device inference is bottlenecked by the ARM64 chip you have, not a server you can upgrade. No API is exposed, so there is no path to building a pipeline around Eva or connecting it to other tooling. The open-source repo has 1 star and 0 open issues at time of curation, meaning community support is effectively nonexistent.

Heptabase

The core workflow is whiteboard-plus-card: you drag notes, PDFs, YouTube transcripts, and highlights onto an infinite canvas and draw the connections your thinking actually requires. Bi-directional links, a block-based editor, Readwise and Zotero integrations, and a web clipper mean most of your existing capture habits plug in without a migration project. The AI Tutor feature, described by the vendor as generating structured, personalized learning sessions with lesson plans and tracked progress, extends this into active study rather than passive filing. The ceiling appears when your workflow needs programmatic access — no API is available, and there is no self-hosted option, so teams with data-residency requirements or custom pipeline needs hit a wall immediately. Power users working around the AI credit limits on lower tiers report switching to Notion AI or Obsidian with plugins for anything that requires bulk AI operations.

Attribute	Eva	Heptabase
Pricing	Free	Paid
Price	—	$8.99/month
Free trial	No	No
Open source	Yes	No
Has API	No	No
Self-hosted option	Yes	No
Platforms	Android	Mac, Windows, Linux, iOS, Android
Pros	Entire stack — language model, voice, maps, documents, Wikipedia — runs on-device with no network calls, so user data never reaches a third-party server even when the app is actively used. Open-source under a public GitHub repo with a downloadable APK, so you can audit the code, build from source, or self-host the distribution instead of depending on a vendor's continued operation. Background music playback with lock-screen controls persists while you use Chat or Docs tabs, so switching to ask a question does not interrupt the media session. Document-grounded chat runs locally, which means you can feed private files into the assistant without those documents ever leaving the device — a constraint that eliminates most cloud-based RAG tools from contention. No account creation or sign-in required, so there is no identity surface to compromise and no subscription to manage.	Whiteboard-plus-card canvas keeps PDFs, highlights, web clips, and notes on the same surface, so you stop losing the connection between a source and the thought it triggered. AI Tutor generates structured syllabi and tracks lesson progress across sessions, which means you get a guided curriculum from your own imported material instead of starting each study session from scratch. Bi-directional links combined with Readwise and Zotero integrations mean your existing capture workflows feed directly into the knowledge base without rebuilding your habits. PDF annotation and web clipper are native rather than third-party add-ons, so highlights stay attached to the original source when you move it onto a whiteboard. CLI compatibility with Claude Code and Codex, as described by the vendor, lets technically inclined users script against their local knowledge base — covering the gap for users who want some automation without a full API.
Cons	Inference speed is hard-capped by the phone's ARM64 chip — on mid-range or older Android hardware, response latency becomes unusable for anything beyond short queries, and there is no server fallback to compensate. No API, no webhook, no automation surface of any kind: Eva cannot be called from a script, integrated into a workflow, or connected to another tool. Any team that needs Eva's capabilities as a component rather than a standalone app will rebuild the functionality from scratch elsewhere. The repo shows 1 star and 0 contributors beyond the original author at time of curation — when something breaks on a specific Android version or model, there is no community to surface a fix or workaround. The APK targets arm64-v8a only, so devices outside that architecture are unsupported with no documented path to building for other targets.	No API is available. Any team that needs to pull notes into an external pipeline, sync with a custom CRM, or trigger Heptabase actions from another system cannot do it — they build a manual export workflow or move to Notion, which exposes a full REST API. No self-hosted option exists. Researchers handling sensitive data — clinical notes, proprietary findings, anything governed by institutional data policy — have no path to keep data off vendor infrastructure. That condition alone eliminates Heptabase for most enterprise and academic compliance contexts. AI credits are capped on lower tiers. Users running the AI Tutor through dense research sessions report hitting limits before the week is out, at which point the core differentiating feature stops working until the cycle resets or they upgrade — a paid-only resolution. The visual canvas model that makes spatial thinking possible also has a ceiling for very large knowledge bases: community reports describe navigation and search becoming unwieldy once card counts grow into the thousands, at which point users add a parallel tagging or folder system to compensate, effectively maintaining two organizational schemes.

Bottom line

Eva is free while Heptabase is paid; Eva is open source; only Eva can be self-hosted; Eva runs on Android; Heptabase on Mac, Windows, Linux, iOS, Android. Pick the difference that actually blocks you.

Frequently asked questions

What is the difference between Eva and Heptabase?

Eva is Free and open source, while Heptabase is Paid. Compare pricing, free trial, API, platforms, and pros/cons in the table above on AIDiveForge.

Is Eva better than Heptabase?

It depends on your workflow. Use the side-by-side attributes (pricing, open source, API, self-hosted, platforms) to decide. AIDiveForge does not rank a universal winner — we publish verified facts so you can choose.

Eva vs Heptabase: which should I pick?

Pick Eva if its pricing model, openness, or platform fit matches your constraints; pick Heptabase otherwise. Check free-trial availability on each listing if you want to test before committing.

Comparison data is sourced and verified by the AIDiveForge data pipeline. AIDiveForge is editorially independent.