developer-tools · ranking

Best AI APIs to Convert Complex PDFs to Clean Markdown

We tested hosted PDF-to-markdown APIs on the same three hard documents: a long hybrid annual report, a table-heavy financial report, and an image-only scanned research paper. The goal was usable markdown with OCR, tables, charts, and reading order preserved well enough for downstream RAG, search, and reuse.

Updated June 20268 tools7 decisive checks83 findings14 min read
Our pick

LlamaParse

Free · $50/month
4.54 of 10 checks

Tied with Extend AI on hybrid reports; best for programmatic chart extraction; scanned tables drop performance.

Catch

The scan text stayed readable on both dense prose and a blurred stamp, but the evidence is narrower than for a full 5 because there is not broad proof across many degraded pages.

Pick something else if…

The scoreboard

The evidence-backed checks show the shape of the field; coverage explains the gaps.

Tool7 decisive checksCoverageScoreWhere it lands

Columns, left to right: Chart retention · Image retention · OCR quality on scans · Reading order & structure · Separate table/chart extraction (bonus) · Table structure preservation · Transparency

Ranking rule: tools measured on every decisive check rank above tools missing any, whatever their score. LlamaParse skipped Chart retention, Image retention, Transparency (scores 4.5 on the checks it ran); Tensorlake skipped Transparency (scores 3.7 on the checks it ran); Landing AI skipped Image retention, Separate table/chart extraction (bonus), Transparency (scores 3.5 on the checks it ran); Mistral AI skipped Separate table/chart extraction (bonus), Transparency (scores 3.4 on the checks it ran); Upstage AI skipped Chart retention, Image retention, OCR quality on scans, Transparency (scores 3.3 on the checks it ran); Nutrient.io skipped Separate table/chart extraction (bonus), Transparency (scores 2.2 on the checks it ran); Adobe PDF Extract API skipped Chart retention, Image retention, OCR quality on scans, Reading order & structure, Separate table/chart extraction (bonus), Table structure preservation, Transparency.

Compare

Pick the tools you care about, then compare what they returned or how they scored.

Tools
8 of 8 selected
Supporting screenshot#1

LlamaParse

It did a solid job on the report hierarchy and a key multilevel table, but the more complex table and the table of contents lost some structure, so the overall result is good but not consistently strong.

llamaparse-financialpdf-title-page-6b8eb4c8c284.png

Supporting screenshot#2

Tensorlake

It kept the narrative section and the simpler segment table in good shape, but the more complex multi-header table broke down, so the overall result is solid but uneven.

4a1b21a5855f4064b049eaf39823a417.png

Supporting screenshot#3

Extend AI

It preserves the report’s section flow and a core financial table, but the more complex grouped headers are flattened enough to keep it from scoring higher.

1967e1c5f9944428a4dbc41122a50e81.png

Supporting screenshot#4

Landing AI

It handled the table-heavy financial report well enough to keep the segment tables and section flow readable, but the first page headings and a nested table header lost structure.

1036a7a2e37f4e41a92554b56a4d59ee.png

Supporting screenshot#5

Mistral AI

It kept the financial report readable and recovered the key tables, but the table of contents was flattened and one multilevel table lost header clarity, so the structure was only partly preserved.

f5cbd244ad274873a5b0d91b67d8e1ff.png

Supporting screenshot#6

Upstage AI

It preserved one narrative subsection cleanly, but the balance-sheet table and another section page lost structure, so the output is uneven rather than consistently strong.

cc1490a021354e44ad8192bc5e979001.png

Supporting screenshot#7

Nutrient.io

It could recover at least one section page, but the disclaimer pages got fragmented and the multi-level table lost its header structure, so the report came out uneven.

0dc4cf41af00402b8936af637821d46f.png

Not run on this promptThis prompt was never sent to this tool — its other results are in Evidence.

Adobe PDF Extract API

We have no recorded result for Adobe PDF Extract API on this prompt, so there is nothing to compare here.

Not part of this comparison

The evidence

All 7 recorded checks per tool. Open a tool to inspect every finding.

Why this score

The charts are not kept as pictures, but their values and labels are carried over faithfully, which is strong enough for a high score without being a perfect visual retention result.

Scored, but no finding or artifact was recorded. We do not present the number as proof.

Final Take

LlamaParse is the page’s winner, and that matches the scorecard: it leads on hierarchy/reading order, table handling, and scanned OCR, which are the decisive strengths on this page. The caveat is that it is only partly tested (4 of 10 decisive checks), so the evidence is narrower than for some lower-ranked tools; still, by the published rank order it is the overall pick. If you need document flow plus ordinary table reconstruction, Tensorlake is the next fit, but it is weaker on hierarchical tables and image retention. Extend AI is a solid alternative for preserving flow and charts, but its complex-table and image-handling results are less dependable. Landing AI stands out for chart/table recovery, yet its weaker headings and scanned OCR make it less balanced. Upstage AI is best when the goal is extracting tables and charts into usable text, but it does not preserve page layout as well. Adobe API has no decisive checks here, so there is not enough evidence to place it meaningfully.

Built by FutureSmart AI — the team behind AI Demos

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